Environmental policy as an important part of public policy plays an active part in the environmental control and protection.It is an intrinsic requirement for the audit institutes to play an supervising and evaluating role in the different stage of environmental policy making，execution and termination.Hence，the environmental policy audit plays an important role in the optimization of policy design，the promotion of the policy performance，the evaluation of policy effect，and the service of environmental control.On the basis of the review of relevant literature，this paper first explores the working mechanism of environmental policy，then based on the public policy process，further analyses the real dilemma of applying such environmental policy at the present stage，and finally puts forward some realistic approaches to perfect the environmental policy.