Cage culture is an important part of aquiculture in China. In view of the large-scale development of cage culture, a remote automatic feeding system for cage culture was designed based on the positive pressure pneumatic conveying technology. The feeding system is installed on the floating culture management platform and consists of loading device, conveying and feeding device and automatic control device. The main structure and working principle of the feeding system were introduced, and the main parameters were analyzed and designed. PLC, the core of the control system, controls the feeding amount of screw feeder by frequency in an automatic and centralized manner according to the conveying pressure. The system performance tests were carried out to test and analyze the feeding amount and crushing rate of feeds with diameters of 6 mm, 8 mm and 10 mm respectively. The test results show that the average minimum feeding amount is 523.2kg/h, which meets the design requirements, and the maximum crushing rate is 1.12%. With the same conveying distance, the larger the diameter, the lower the feeding efficiency and the greater the crushing rate. Research shows that, through the integration of feeding system and culture management platform, the applicability of automatic feeding system can be further improved.