Abstract: In order to solve the problem of “heavy electricity and light agriculture” existing in the context of the rapid growth of agricultural light complementary projects under the background of “double carbon”, this paper established the whole life cycle cost/benefit model of agricultural light complementary projects, established the economic benefit evaluation model under three modes of independent operation mode, cooperative operation mode and lease operation mode.It determined the optimal operation strategy of agricultural light complementary projects through sensitivity analysis.The results showed that technical factors and agricultural economic factors affected the economics of agricultural light complementary projects at the same time.Considering that the independent operation mode was the optimal operation mode of agricultural light complementary projects under carbon emission constraints, it could significantly improve the overall income of agricultural light complementary projects by reducing agricultural operating costs and improving agricultural operation income.