Objective To explore the clinical application value of transvaginal ultrasound in monitoring follicular development and endometrial thickness changes, providing a reference for assisted reproduction and infertility treatment. Methods A retrospective analysis was conducted on the clinical data of 80 patients who received transvaginal ultrasound monitoring in Zhanlanlu hospital Xicheng District of Beijing from October 2022 to October 2024. Dynamic changes in follicle diameter, quantity, and endometrial thickness were recorded and analyzed for their correlation with ovulation and pregnancy outcomes. Results Transvaginal ultrasound effectively and dynamically visualized follicular development and cyclic endometrial changes. The probability of ovulation significantly increases when follicle diameter ≥ 18mm, while the relatively high pregnancy rate was observed when endometrial thickness was between 8 ～ 12mm (P<0.05). Conclusion Ultrasound monitoring can effectively predict ovulation time and evaluate endometrial receptivity, guiding ovulation induction therapy and embryo transfer timing selection. Transvaginal ultrasound monitoring of follicular development and endometrial changes has high clinical practicality and can provide reliable support for the diagnosis and treatment of infertility and assisted reproductive technologies.