The invention aims to provide a method for calculating the opening range of a natural fracture during temporary plugging and fracturing. The method comprises the following steps: A, establishing a fracture expansion physical model under a temporary plugging condition; B, establishing a fluid flow model in the crack, and calculating an overall induced stress field of the crack; C, solving to obtainfluid pressure and crack width distribution, and judging whether the rock mass meets the damage condition or not; D, based on a solving idea of a fluid flow model and a crack induced stress field model in the crack, dynamically simulating a crack propagation process under a temporary plugging condition; And E, inputting basic parameters to judge the opening range of the natural crack, and analyzing the influence of each parameter on the opening range of the natural crack. Based on the distribution condition and the change rule of the induced stress field around the hydraulic fracture before temporary plugging, the opening rule and the opening range of the natural fracture under the action of the induced stress field of the hydraulic fracture after temporary plugging analysis is carried out on the interior of the hydraulic fracture.