The invention provides a real-time measuring system for impact temperature and spectral emissivity. An output laser of a continuous laser in the measuring system is modulated by a high speed acousto-optic modulator into double pulse lasers with a constant energy ratio, the double pulse lasers are irradiated on the surface of a to-be-measured sample respectively before and after an impact wave arrives at the surface of the to-be-measured sample and are received, together with a heat radiation optical signal generated by the to-be-measured sample due to impact, by a double optical fiber probe, and a multichannel radiation pyrometer is used for detection. The spectral emissivity and the impact temperature of the to-be-measured sample can be calculated at the same time through measurement of the change of the amplitude of a double pulse laser signal and the amplitude of the heat radiation optical signal. According to the invention, all the optical signals are transmitted in optical fibers, which facilitates measurement in a complex environment, the output power of the continuous laser can be continuously and independently adjusted, time response of the double-pulse lasers is fast, changes of reflectivity on the surface of the to-be-measured sample before and after impact can be reflected in real time, so the real-time measuring system is applicable to measurement of spectral emissivity and impact temperature in different temperature ranges.