Abstract: Based on the textbook Elasticity by Wu Jialong, and the "trilemma" characteristics of the course, taking the common questions in the stress state theory as examples, the stress vector, the normal stress, the shear stress, the principal stress, the principal direction of the applied force and the maximum shear stress on any differential inclined plane are included. The Matlab-GUI module is used to compile the stress state theory solver, By processing the inputting physical parameters and displaying results, the thinking process of the elasticity is reproduced and the mathematical solution is verified, the complex abstract mechanical formulas and the differential slope results are clarified in graphic visualization, so that the students' abstract thinking and mechanical thinking are linked. The stress state theory solver of elasticity can provide a reference for students' mechanics learning and for mechanics teaching.