1. The time of semen specimen collection is usually 2-7 days of abstinence. Abstinence time too short (<2 days) or too long (>7 days) is not suitable for semen examination. 2. Semen specimens should be collected intact in the designated container and no semen should be missed. Otherwise, the accuracy of the test results will be affected. 3. The sperm of the subject may change over a period of time, and the range of variation can sometimes be large, so an accurate judgment of the semen results cannot be made based on only one specimen.