Secondary infertility mainly involves four examinations, namely sperm examination, ovarian function examination and ovulation monitoring, tubal examination and endometrial examination, as follows: 1) semen examination, that is, semen routine, a simple semen routine can basically rule out most causes of male infertility; 2) ovarian function examination and ovulation monitoring, because pregnancy requires the assessment of ovarian function to ensure that there are mature and healthy eggs. The ovarian function check and ovulation monitoring, because in order to get pregnant, we need to assess the function of the ovaries first, and then by monitoring ultrasound, hormones and basal body temperature, we can determine whether there is normal ovulation; 3, tubal examination, the main purpose of tubal examination is to determine whether the tubes are open, generally there are two ways of tubal water and tubal imaging, it is recommended to do tubal imaging is more clear and accurate; 4, endometrial examination, generally in the ultrasound monitoring ovulation, but also monitor whether the endometrium is thick enough, and the uterus endometrium is intact and normal in shape.