The utility model discloses a line tightening tool checker for an electric power line, which can simulate the work state of a line tightening tool of the electric power line, can be used for checking the mechanical performance of the line tightening tool in a work load and the use condition of the tool and can help people to discover the existing potential hazard in time. The checker comprises a support mechanism, a checking mechanism and a damping mechanism, wherein the checking mechanism and the damping mechanism are respectively arranged in an upper chute and a lower chute of the support mechanism, the checking mechanism and the damping mechanism are used for fixing the line tightening tool, and the line tightening tool is operated and checked according to a conventional method. The defect that the line tightening tool is not provided with a daily checker is overcome, and the daily checking of the line tightening tool is convenient. The work condition of the line tightening tool under the work load can be really simulated, the checking on the mechanical performance and the completion condition can be carried out, and the reliability and the safety of the work of the line tightening tool are improved. The hidden defects of the line tightening tool can be discovered in time, the fault occurring probability of the line tightening tool in a work site can be correspondingly reduced, and the work efficiency is improved.