The high-precision self-calibration radiation reference source is currently the research focus of satellite remote sensing calibration. In order to meet the requirements of quantitative applications such as climate monitoring, low-light radiation metering and single photon source radiance measurement, in view of the application requirements and technical requirements of visible to near infrared low-light radiometer, a compact three-channel low-light radiance meter based on correlated photon self-calibration is designed. This design method can improve the measurement accuracy of low light irradiance by using objective physical effect instead of physical standard, reducing the cumulative error caused by standard transfer chain. The absolute calibration of the detector responsivity can be achieved by the spontaneous parameter down-conversion effect, and the absolute radiation observation can be achieved without relying on the external reference. Based on this study, combined with the special application requirements of radiance meter, a numerical model of spectral rate and geometric transmission characteristics of wide spectrum correlated photons is established, and two basic operating modes of self-calibration and radiation observation are determined. The interaction between 355 nm pump source and nonlinear medium generates three-wave mixing, and the correlated photons are generated by class I non-collinear spontaneous parametric downconversion, the combined effect of monochromatic pump photon flow and quantum vacuum noise on non-centrosymmetric nonlinear crystal makes each incident photon spontaneously split into two photons with lower energy with a certain probability, called signal photons and idle photons respectively, they have a wide sptrum distribution from pump wave frequency to lattice resonance frequency. Correlated photon source has the technical characteristics of time and space correlation, natural wide spectrum and absolute reproducibility, so it has high absolute accuracy. Integrated design of self-calibration and radiation observation can monitor and correct changes in response characteristics in real time, maintain long-term stability of response characteristics, and improve traceability and accuracy of observation data. This design method solve the key technologies such as preparation and value transfer of correlated photon sources, suppression of pump stray light, high precision and high efficiency coupling of correlated photons, UV radiation resistance of space single-photon detectors, packaging reinforcement technology of space single-photon detectors,self-calibration and integrated design of radiation observation. The spectral measurement range of the low-light radiance meter is from 460 nm to 1 550 nm, the measurement range of radiance is 1×10^-9~1×10^-6 W/(cm²·sr·nm). In the design, the integration, miniaturization and modularization of the whole system are considered, and the eight spectral bands are integrated into a three-channel structure, solving the preparation of wide spectrum dependent photon source, optical multiplexing of calibration optical path, radiation measurement, high precision coincidence measurement and full optical path calibration of radiance meter, and achieving high precision radiation observation from visible to near infrared and periodic self-calibration research targets. In the self-calibration mode, the multiplex optical path module periodically introduces the spontaneous parametric down-conversion correlated photons, and the photon counting and coincidence detection module are used to calibrate the absolute quantum efficiency of the three channels. In the radiation observation mode, the multiplex optical path module introduces the low-light level target radiation and obtains the absolute spectral radiance of the observation target in the band of 460~1 550 nm at the same time. The calibration coefficient obtained by the self-calibration mode is used to correct the observation results. The effects of link error limited by radiation reference value transfer, optical decay of optical path and electronic decay of optical path on the measurement accuracy of microradiance are fundamentally solved. The visible near-infrared band adopts free space coupling mode and the short-wave infrared band adopts multi-mode fiber coupling mode. Through design optimization analysis, the focusing spots of the first and second channels meet the 300 μm pixel requirement of Si single photon detector, and the focusing spot of the third channel meets the 62.5 μm core diameter and 0.22 numerical aperture requirement of multi-mode fiber, all of them can be received by the detector photosensitive surface, meeting the design objectives. The method based on correlated photon calibration does not need to trace the high-precision primary standard in the laboratory and the lengthy standard transfer chain. By using the correlated photon generated in the process of parametric down-conversion, the calibration source of time, space and polarization can be obtained, and the high-precision observation of the low-light spectrum radiance from visible to near infrared band can be realized. The solution to the scientific problem of low-light observation instrument in space platform measurement can obtain higher calibration accuracy, and play an important role in climate monitoring, low-light radiation metrology, single-photon source radiance measurement and so on.