In recent years, China has been increasing the input of fishery technology, but the performance of China's fishery technology efficiency and whether the structure of fishery factor input is reasonable deserve attention. In this paper, CD stochastic frontier production function was used to analyze the structure of fishery factor input and fishery technical efficiency through 232 sets of panel data from 29 provinces from 2012 to 2019. The results showed: ① the flexibility of labour, aquaculture area, the vessel power and fish fry showed a trend of increase, but in addition to the fish fry, the contribution of labour, aquaculture area, and the vessel power are negative, moreover the input of labour, aquaculture area, and the vessel power are excessire; ② China's fishery returns to scale are low, the utility of returns to scale has not yet been realized, the production efficiency is low, and the input of fishery technology factors is insufficient; ③ China's fishery technical efficiency is lower than that of other agricultural industries, but the fishery technical efficiency shows an increasing trend. The technical efficiency of coastal areas is greater than that of inland areas. Research shows that low technical efficiency of fishery is correlated with factor input synergy, and unreasonable factor allocation is the main reason for low technical efficiency, so factor input synergy can promote the improvement of production efficiency.