Because the portable Leeb Hardness Tester is small and easy to carry, it has little damage to the surface of the material object. It can quickly detect the hardness of different types of raw materials in different forms, and can also realize the conversion between different hardnesses, effectively improving the use efficiency of testing personnel, and has been recognized as a Widely used in various experimental departments and units. However, because the testing personnel are not familiar with the working principle, incorrect operation will affect the correctness of the testing data. This article, edited by NBCHAO Mall, takes the TH110 Leeb Hardness Tester as an example to discuss the factors that affect the error of the testing results.