Abstract: In the process of providing technical services to our customers, many customers give the feedback that the measured strength of the cement tested was always about 3~5MPa lower than that of the cement tested by our company itself. According to the analysis, it is found that the factors affecting the test result of cement strength mainly include the quality of standard sand, the curing condition of cement test sample and the performance index of compression fixture. The cement strength testing should be carried out in strict accordance with national standards to ensure the authenticity and accuracy of the testing results.