Considering the effective utilization of power battery, the cascade utilization was introduced power battery closed-loop supply chain, the system decision-making problem of the power battery dual circulation closed-loop supply chain composed of a manufacturer, recycler and cascade utilization enterprise was the research object. Under the scenario of government subsidizing cascade utilization enterprise and manufacturer sharing the innovation cost of cascade utilization, this paper (1) constructs a differential game model of the closed-loop supply chain dynamic system; (2) studies the equilibrium strategy of each game participant under the dual mechanism of government subsidy and cost-sharing; (3) analyses the influence of each parameter on the decision-making of main bodies by numerical simulation. The results show that with the increase of government subsidies, the utility of cascade utilization efforts will increase, the cascade utilization enterprise will reduce the sale price of cascade utilization products, the recycler will increase the wholesale price of high energy density batteries, the manufacturer shares part of the innovation cost of cascade utilization enterprise, which helps to reduce the burden of cascade utilization enterprise, and the government subsidy and coordination mechanism of cost-sharing are conducive to improving the level of cascade utilization.