Objective To investigate the efficacy and safety of a single induction dose of cyclopofol in painless four?dimensional hysterosalpingography， this study aims to assess its academic significance and adherence to Nature journal's publication standards. Methods A total of 120 patients admitted to Guangdong Reproductive Hospital between February 2022 and December 2022， requiring painless vaginal four?dimensional ultrasound hysterosalpingography， were selected as the study population. Random selection was performed with 40 patients in each group. The dosage of cyclopofol administered was 0.3 mg/kg （C1 group）， 0.5 mg/kg （C2 group）， and 0.7 mg/kg （C3 group）. Heart rate （HR）， mean arterial pressure measured non?invasively using a cuff， time to wake after surgery， and incidence of adverse reactions were observed at three time points： before examination （T1）， during contrast agent injection （T2）， and after examination （T3）. Results There were no significant differences in heart rate （HR） and mean arterial pressure （MAP） between T1 and T3 among the three groups （P > 0.05）. However， at T2， group C1 exhibited significantly higher HR and MAP compared to group C2 （P < 0.05）， while there was no statistically significant difference in HR and MAP between group C2 and C3 at T2 （P > 0.05）. The duration of wakefulness was shorter in group C2 than in group C3 （P < 0.05）， but there was no statistical significance in wakefulness duration between group C1 and C2 （P > 0.05）. The incidence of adverse reactions was lower in group C2 （10.0%） compared to both group C1 （32.5%） and group C3 （37.5%） with statistical significance （P < 0.05）. Conclusion The administration of cyclopofol at a dosage of 0.5 mg/kg exhibits notable advantages in painless four?dimensional hysterotubal ultrasonography， including effective sedation， prompt wakefulness， and a low occurrence rate of adverse reactions.