Based on the computable partial equilibrium model constructed by Francoins and Hall (2003, 2007) and the relevant data of global agricultural production and trade in 2015, this paper simulates the trade and welfare effects of RCEP from the industry level. The main conclusions are as follows: first, because of the large number of member countries, the establishment of RCEP will significantly promote the trade of agricultural products among some members, such as China and Japan, Korea and Japan; However, it has a destructive trade effect on the trade of agricultural products among the member countries that have signed bilateral FTA before. Second, because of the lack of demand elasticity of agricultural products, the impact of RCEP on the output and price of agricultural products of member countries and non-member countries is limited, except Australia and New Zealand. Third, according to the net social welfare indicators, Australia and New Zealand will be the biggest beneficiaries, while ASEAN countries and Japan will suffer welfare losses.