In order to study the application of the distribution law of fishing grounds in shrimp and crab farming， and to solve the problem of over-concentration of feeding in traditional shrimp and crab farming feeding devices， this study completed the mechanical structure and intelligent control system design of the mobile autonomous feeding device through the research of overall structural layout， storage tank， feeding device， garbage collection device， control system and power device， conducted stability and motion feasibility analysis， trial-produced a feeding device prototype and conducted underwater three-dimensional feeding tests. The device can carry 5 kg of bait and feed underwater three-dimensionally through the propulsion device and the Ballast tank. It can simulate the behavior pattern of shrimps in natural waters and optimize the distribution of feed， thereby creating a feeding environment closer to natural ecological conditions. The test results show that the device can feed at 6 different depths underwater， with a feeding speed of 4.9 kg/min， which can meet the needs of intelligent three-dimensional feeding and collect floating garbage generated during the breeding process. The feeding device can feed flexibly and evenly， and can replace manual feeding to reduce labor intensity. At the same time， the intelligent device can be used to record various parameters such as water bodies， shrimps and crabs for research on the distribution of fisheries， assist in the application of fishery distribution laws in aquaculture， and provide new ideas for intelligent and precise farming.