Absolute calibration can be realized by means of correlation photon which is generated by the spontaneous parametric down-conversion. The main difficulty of using correlation photons method to realize the absolute calibration of analog detectors is to acquire ultra-bright entangled photons. The calibration principle and experimental device of acquiring ultra-bright correlation photons were described based on spontaneous parametric down-conversion. A laser (532 nm) was used to pump the nonlinear crystal periodically-poled lithium niobate (PPLN), and ultra-bright entanglement source satisfing the quasi-phase matching (QPM) manner was produced. The measurement result shows good linearity when pump laser power is different. The principle of phase matching technology was described and the preparation of the experiment device of ultra-bright correlation photons was set up, the pump laser light source and the design parameters of the optical components were improved. This novel method shows great significance to high-accuracy calibration for the wavelength of correlation photons and the future researches on analog detector.