Based on the multi-spectral technology and the characteristics of CCD two-dimensional temperature field measurement, this paper proposes a colorful CCD two-dimensional temperature field multi-spectral true temperature online multi-point calibration system. With the analysis of multi-spectral measurement model and CCD measurement model, the approximate relation between the true temperature and the brightness of CCD is deduced during the gas combustion. With multi-spectral multi-points temperature measurement technology, the true temperature to calculate the emissivity and the true temperature of multi-points and use values of the true temperature, the corresponding points of CCD array can be calibrated. Applying the two-dimensional temperature field true temperature calibration system in CO2 laser welding flame, we not only get the variation between the emissivity and the wavelength but also two-dimensional true temperature distribution maps of flame of CO2 laser welding. Multi-spectral calibration technology has the feature of real time and flexible and is a really feasible temperature CCD online multi-points calibration and measurement method.