In recent years, with the continuous expansion of river crab culture area in China, the increase of output and the instability of market price have triggered the risk of river crab culture. Shrimp is favored by farmers because of its fast growth, low investment cost and stable market price. Based on the original technology model of mixed culture of shrimp and crab, aquatic science and technology workers in Suzhou strengthened the management of freshwater shrimp culture by increasing the proportion of freshwater shrimp in crab culture ponds, effectively increased the yield of crab ponds and reduced the risk of crab culture. This double-main-rearing mode of freshwater shrimp and river crab produces 75 kilograms of freshwater shrimp and more than 75 kilograms of river crab per mu every year, with a benefit of more than 5,000 yuan per mu. Now this dual-main culture mode of shrimp and crab has been widely promoted in southern Jiangsu.