The invention discloses a method for determining the intermediate cutting intensity of a natural secondary forest. The method for determining the intermediate cutting intensity of the natural secondary forest comprises the following steps of (1) building a competitive structure unit; (2) determining the minimum number of plants which are reserved; (3) building a function between a competitive structure unit area maximum value and a competitive structure unit average crown radius; (4) carrying out statistics on stand density N reality of the natural secondary forest, obtaining an average crown radius of the natural secondary forest, using the average crown radius as an R, calculating the minimum reservation density N minimum of the forest stand where a sample plot is located through the formula (1), if the N minimum is larger than the N reality, planting forest trees in the natural secondary forest in a supplement mode, wherein the N minimum minus the N reality is equal to the minimum number of the supplemented forest trees, and if the N minimum is smaller than the N reality, carrying out intermediate cutting, wherein the N reality minus the N minimum is equal to the maximum number of plants of intermediate cutting. The method for determining the intermediate cutting intensity of the natural secondary forest is simple, easy and convenient to operate, easy to master and free of cutting analytic trees, intermediate cutting can be rapidly achieved, and unwanted forest resource waste can be avoided.