The National Forest Park is one of the carriers of ecological welfare supply and an important way to balance social development and ecological protection, meet the people's growing needs for a better life. Combining with the system theory and taking Heilongjiang Province as an example, this paper constructs the ecological welfare supply system of the national forest park and sets up the hierarchical structure of the internal elements of the ecological welfare supply system by using the Interpretation Structure Model (ISM). The following conclusions are drawn:(1) The surface factor layer of the ecological welfare supply system contains 8 internal factors, which are directly related to the ecological welfare supply. (2) The middle factor level includes 21 internal factors, which can directly affect the surface layer and is one of the important paths to improve the ecological welfare supply. (3) The deep factor level composes of five internal factors, which are controllable and multipath influencing factors and are the main paths to improve the ecological welfare supply of the national forest park.