Abstract: In order to solve the problem of unreasonable setting of the shearer, this paper studies the theory that the best selection of the range of pre-tightening coefficient is 0.5-1.1. After ANSYS finite element analysis and verification, the pre-tightening coefficient and the maximum contact pressure of the binding surface and the opening value are determined, and the pre-tightening coefficient is 0.5-1.1 to meet the requirements of the project, which has some rationality.