Power generation from agricultural waste not only helps to meet energy demands but also provides an effective way to dispose of agricultural waste. However, in order to boost agricultural waste power generation industry, many factors such as willingness of farmers, high collection cost, and uncoordinated supply chain are the major issues that need to be solved. In the present work, synergetic development of the agricultural waste power supply chain has been studied by establishing collaborative evolution model, and the marginal utility of government subsidy has been defined. Our results showed that in the farmer subsystem, the selling price of agricultural waste is the order parameter of the agricultural waste supply chain and has positive feedback in straw supply chain system, which can lead the development of the system. Increase in selling price can promote the synergetic development of the agricultural waste supply chain. The results indicate that subsidies affect the synergetic development of the agricultural waste supply chain, and an increase in government subsidies will promote the development of agricultural waste power generation system. The findings suggest that a government subsidy of 53 CNY/t would optimize utility, given the existing synergetic system. The results can be helpful for government policymakers to support agricultural waste power generation projects.