The invention discloses a stress calculation method with an accurate analysis result for power transmission tower member bars. The method comprises the following steps: firstly, building a finite element mechanics model of a tower structure by virtue of a finite element method, and carrying out discretization of the whole structure according to the tower structural composition; generating an element stiffness matrix for each element, and generating a global stiffness matrix in a superposition manner by combining with the spatial angle relationships and the connection relationships among the member bars in the tower structure; generating a load array according to the load on the tower, and with a node displacement array as an unknown quantity, forming a matrix equation with the global stiffness matrix, the load array and the node displacement array; and finally obtaining node strain by solving the matrix equation, and obtaining the stress of each member bar in the tower structure. According to the stress calculation method, the stress of the power transmission tower member bar can be directly calculated exactly through a mathematical method; and a scientific basis can be provided for safety evaluation of the tower structure.