There are many reasons for men to have weak erection during intercourse, which may be caused by deficiency of kidney energy, hormone deficiency, or cavernous body congestion and dysfunction. It is best to check the level of sex hormones through blood tests. If the level of androgens is obviously decreasing, you can take oral testosterone undecanoate capsules or Chinese medicine to tonify the kidneys and benefit the qi, such as eight flavors of Yi kidney pill and Qilin pill, and treat the symptoms for 1-2 months, so that the weak erection can be effectively improved. If it is caused by penile cavernous body blood filling dysfunction, it is necessary to pass penile blood flow Doppler examination to make a clear diagnosis. To control the frequency of sex, not more than 2 times a week, too much sex can also lead to weak erection.