Scene monitoring algorithm based on single-pixel imaging system was investigated. The algorithm based on compressed sensing that uses scene detection intensity difference as measured value can be used to obtain a scene change information. The results from the proposed method and traditional method were compared using computer simulation experiments. For a simple binary scene, the accurate change information can be obtained under the sample rate 0.01. For a gray scene, because information becomes large, the number of samples required increases, but at the same number of samples, the proposed method can be used to obtain more accurate results than that of traditional method. Simulation results show that the proposed method can be used to obtain accurate scene change information at low sample rate, and reduce the computational complexity. It will have a reference value in the scene monitoring based on single-pixel imaging system.