Decrease in menstrual flow after abortion is an abnormal phenomenon in clinic, the reason why there is a decrease in menstrual flow may be due to the following conditions: First, endocrine disorders, it is recommended to take a blood test of sex hormone six on the 2nd-3rd day of menstruation to find out whether there is an increase in prolactin and androgen, if the level of the two hormones mentioned above is elevated, it may lead to a decrease in menstrual flow. Secondly, if the menstrual flow decreases after abortion, and it is more than 1/3 less than the previous menstrual flow, clinically, it may be due to the damage of the endometrium causing incomplete adhesion of the uterine cavity, so it causes the decrease of menstrual flow, combined with the clinical history, combined with the laboratory, ultrasound examination, comprehensive analysis is given, and hysteroscopy can be done when necessary, to separate the adhered tissues, which can be expected to return the menstrual flow to normal. If necessary, hysteroscopy can be performed to separate the adherent tissues, which is expected to restore menstruation to normal.