Deadline anchor is a basic component for oil drilling rigs and workover rigs to measure the actual hook load information, and is used for monitoring and diagnosis of the working state of the downhole drill string. Aiming at the problem that the sheave is prone to damage and failure in the actual use of the deadline anchor, taking the JZG72 deadline anchor as an example, engineering mechanics and ANSYS Workbench software were used to make analysis and calculation. The hole eccentricity has a great influence on the strength of the sheave. The method of adjusting the eccentricity of the shaft hole improves the strength reserve and safety of the sheave, which has the advantages of not increasing the geometric size and weight of the material, not needing high-grade steel, reducing cost.When the eccentricity of the shaft hole varies between 0~160 mm, the maximum equivalent stress on the sheave is the smallest (23989 MPa) when the eccentric distance is 120 mm, which is less than the allowable stress of the material Q345E, and meets the strength requirement that the safety factor ns is 1.4. The calculation and analysis show that when the eccentricity of the sheave shaft hole changes, the maximum equivalent stress of the dead-rope fixer sensor arm and the rope clamp arm are in a safe state as a whole.