This paper applies fuzzy system to establish the input-ouput model of China's regional economy. As the relation between production factors and economic output is nonlinear and complicated, the black-box nature can be resolved by fuzzy system. Firstly, according to Cobb-Douglas production function, select capital assets, human capital, plowland as input factors, GDP as economic output; secondly, divide 31 areas into three clusters based on economic development lever; finally, construct the Takagi-Sugeon model by fuzzy neural network, and three fuzzy if-then rules are abstracted. The result shows that the fuzzy model has better simulation precision than traditional regression, and the fuzzy rules can give valuable decision-making for regional economic growth macroscopically.