The mild ovarian stimulation protocol is a treatment protocol for in vitro fertilization-embryo transfer using clomiphene, letrozole, low-dose gonadotropins and other drugs to promote ovulation without downregulation, which is becoming more and more accepted because of its advantages of “safety, efficiency and less interference”. Microstimulation is mainly used in the following cases: 1) Patients of advanced age with reduced ovarian reserve; 2) Patients with poor quality eggs from previous conventional regimens: the number of mature eggs obtained by microstimulation is reduced, but the quality of eggs is higher. The application of fluorescence in situ hybridization technique to screen pre-transfer embryos revealed that the rate of normal embryos obtained by the microstimulation protocol was higher than that of the conventional protocol. 3. Poor ovarian response to conventional regimens: Clinical practice has confirmed that increasing the dose of stimulation drugs for poor ovarian response does not significantly increase the number of follicles, improve egg quality and increase the pregnancy rate, while facing the side effects and expensive costs associated with high dose stimulation. Microstimulation protocols reduce the dose of stimulating drugs, shorten the treatment time, and increase the number of cycles to obtain better quality embryos to achieve the desired pregnancy rate. 4. A small number of patients with polycystic ovary syndrome and previous ovarian hyperstimulation: microstimulation is a more economical and safe method to control the number of follicle development by minimizing the effective dose of ovulation and reducing the patient’s discomfort and risk of ovarian hyperstimulation. However, microstimulation has problems such as early follicular discharge during ovulation, low egg acquisition rate, low number of embryos available for transfer, and relatively low clinical pregnancy rate. How to choose the best treatment plan to obtain high quality eggs and embryos and avoid complications requires the clinician to develop a personalized treatment plan that is optimal and cost-effective for the patient, and requires active cooperation and communication between the patient and the physician.