Background: One of the characteristics that is directly linked to polycystic ovary syndrome (PCOS) is body mass index (BMI), and there have been numerous studies that are pertinent to PCOS patients with high BMI. However, further research is needed to determine the precise impacts of normal BMI on PCOS patients’ metabolism and chances of becoming pregnant. Achieving a normal BMI may enhance glucose metabolism and lower the risk of gestational diabetes in pregnant PCOS women. By examining the reproductive results of PCOS patients with normal BMI, this study offers fresh suggestions for the management and alleviation of clinical symptoms in PCOS patients. Methods: From January 1, 2021 to April 30, 2022, 133 in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cases with normal body mass index were enrolled in the Reproductive Medical Center of Hainan Women and Children’s Medical Centre, including 77 PCOS patients with normal BMI and 46 non-PCOS patients with normal BMI, the ovulation induction regimen was used as an antagonist regimen, and the waist circumference, body mass index, follicle-stimulating hormone (FSH), luteinizing hormone (LH), LH/FSH, anti-Mullerian hormone (AMH), blood lipids, homeostasis model assessment of insulin resistance (HOMA-IR), gonadotropin (Gn) dosage between the two groups were compared, Gn days of use, number of eggs obtained, normal fertilization rate, normal cleavage rate, number of available embryos, number of high-quality embryos, embryo implantation rate, clinical pregnancy rate and other indicators. Results: The endocrine situation between the two groups showed that the AMH, LH value, LH/FSH value, fasting insulin and HOMA-IR of PCOS group (group 1) were significantly higher than control group (group 2), and the data between the two groups were extremely significant (p < 0.01), the basal testosterone value and blood lipid in group 1 were higher than group 2, and the difference between the two groups was statistically significant (p < 0.05). The ovulation induction and embryo conditions between the two groups showed that the amount of Gn in group 2 was extremely significant (p < 0.01) higher, the number of eggs obtained, normal fertilization, normal cleavage and available embryos in group 1 were higher, the differences were extremely significant (p < 0.01), and the differences in other indicators were not statistically significant (p > 0.05). The results of kendall analysis showed that BMI, lipids, and AMH, and of PCOS patients with normal body mass index were significantly positively correlated with HOMA-IR (R > 0, p < 0.05). The basal testosterone (T) values of PCOS patients with normal body mass index were positively correlated with HOMA-IR (R > 0, p > 0.05), and the clinical pregnancy rate was negatively correlated with HOMA-IR (R < 0, p > 0.05). BMI was significantly negatively correlated with clinical pregnancy rate (R < 0, p < 0.05). Conclusions: Patients with PCOS with normal BMI should be treated with hyperandrogen control and insulin resistance therapy, and weight loss is recommended despite a normal body mass index. This study found that the Gn dose of PCOS patients with normal BMI should be lower than that of non-PCOS patients, which would be more conducive to pregnancy in PCOS patients.