Abstract: Abstract: In recent years, with the construction of various large-scale aquaculture facilities at home and abroad, it has opened the prelude for the aquaculture industry to enter the deep sea and expand the aquaculture space outside the bay. In response to trends to promote the transformation and upgrading of the aquaculture industry, the author’s research team is developing large-scale lifting rigid cages that are suitable for the bottom waters outside the bay. In order to solve the problems of feeding management in the net cages culture, we have developed a floating auto-feeding system. The system uses built-in batteries to provide the energy, and offshore automatically realizes a series of precise actions such as timing, fixed-point, and quantitative feeding of bait with the help of a built-in PLC control program. At present, the miniaturized prototype of the system has been developed and preliminary experiment has been carried out. The total volume of the feed bin is 0.23 m3, and the total volume of feed storage is 164 kg. The four independently controlled feed bins can realize to feed at different intervals. The average feeding ability is about 66.09 kg?min-1 (size of bin door opening: 90 mm×100 mm). The preliminary experiment shows that the floating auto-feeding system basically meets the design requirements. It has the advantages of simple structure, strong performance in adapting to harsh sea conditions, convenient operation, accurate feeding action, low failure rate, and stable operation, etc.