In view of the actual requirements of on-site monitoring of aquaculture, a portable underwater camera system was studied and designed to observe the bottom quality and the growth and development of aquaculture in water with visibility less than 10cm. The underwater camera system with low visibility could enhance the clarity of underwater camera in water with low visibility by optimizing the optical path of the camera system, adding clear water tank, using low illumination CMOS camera, and correcting the color of the captured images in real time. The test and application results show that: in the water with visibility less than 10 cm, the underwater camera system with low visibility is superior to the common aquatic product inspection camera in terms of the mean brightness, standard deviation, information entropy, UCIQE, UIQM and other indicators. The research shows that when the depth of the breeding pond is less than 2m and the water visibility is less than 10cm, the underwater camera system with low visibility can meet the detection of the low visibility underwater environment.