The traditional underwater active laser scanning system uses ordinary camera to receive and record reflected light. The reflected laser point is buried in the background noise and cannot be separated, which affects the image quality. In this paper, the position and direction information of laser reflected light and scattered background stray light are recorded by light field camera in underwater laser active scanning imaging system, providing the possibility to suppress scattering background stray light. In the subsequent processing of light field recording image. Firstly, the recorded light field images are refocused twice. The first is the refocusing of the laser light spot on the object surface and the second is the refocusing of the scattered light in the foreground of the laser light spot. Then, the differential processing is applied to the two refocusing images, and a computer automatic judging process is proposed to make the contrast of laser point on the differential image maximum or large enough. The experimental results show that the above method can effectively suppress the scattering background, and it will be a necessary supplement to the existing space separation scattering background suppression technology of synchronous scanning active laser imaging system.