The intensity correlated quantum imaging experiment and application with thermal light restricted by the high bright thermal light to some extent. The coherence time is shorter,and the number of photons in a coherent cellular is smaller because of true thermal light,so true thermal light is replaced by pseudo-thermal light,which can be obtained by a laser transmitting through rotary ground glass. When a nanosecond laser is used,the source simulates the intensity fluctuation of true thermal light extremely,and obeys to Gauss statistical distribution property. In addition,the important property is that the measurement to intensity fluctuation isn’t limited by finite pass band of the photo-detector. Even in the case of slower response detector,the intensity fluctuation can be recorded accurately,and the light field is cross-spectrally pure.