Screening machine is mainly used in grain sorting, classification grain processing industries. Its key structural component, screen box, plays a key role in ensuring the credibility service life of the screening machine. In order to test the bending stiffness of the screen box to determine the design effect of the prototype machine, the blender can be used in the design scheme the whole production process of the screening machine, which can be carried out by means of finite element analysis experimental analysis. Although the finite element analysis design scheme of mixer shed is a more visualized low-cost way, it is very difficult to accurately calculate the main parameters of various forms only based on a simple theoretical model. In many cases, the results of finite element analysis are quite different the dynamic response in specific cases. Reliable results can only be obtained by integrating the finite element analysis method with the experimental multi form detection statistical analysis method carrying out mutual authentication. In this paper, taking zkb2575 linear screening machine as an example, two experimental methods of manual hammering multi form detection automatic vibration multi form detection are designed. The comparison of vibration analysis results can be obtained by fusing each other, which shows the basis for testing the bending stiffness of screen box.