In this paper, the revised content and new content of the JB/T 4307 “cement mortar for insulators” standard are mainly introduced, including the revision of the classification of cement mortar, the increase of the types of aluminate cement and the technical performance index. In order to improve the reproducibility, comparability and accuracy of the test results, it is first defined that after preparation and curing of cement samples under working conditions, and then the test is carried out through the standard condition curing to the specified age after the demoulding. The water absorption and dry shrinkage ratio of the cement mortar are used as the mandatory indexes of the type test, and the temperature cycle test, low temperature test and freeze-thaw cycles test are used as the protocol test to evaluate the long-term stability of physicochemical properties and durability of the cement.