Objective To evaluate the clinical efficacy and safety of simultaneously integrated boost-intensity modulated radiotherapy（SIB-IMRT） to the tumor center in the initial stage in patients with bulky cervical cancer with acute bleeding. Methods Retrospective analysis was performed on the clinical data of the patients with bulky cervical cancer with bleeding who received SIB-IMRT to the tumor center in the initial stage in the Radiotherapy Department of Affiliated Hospital of Nanjing University of Chinese Medicine from January 2019 to January 2023. The propensity score matching method was used to match patients receiving SIB-IMRT to the tumor center in the initial stage with those receiving conventional IMRT. A total of 20 pairs of 40 patients were included in the study. In the SIB group 15 Gy in 3 fractions was delivered to the tumor center （the region that was the subtractive margin from the tumor boundary by 1.5 to 2 cm）, and simultaneously 46 Gy in 23 fractions was delivered to the periphery of tumor and lymphatic drainage area of pelvic cavity at the initial three times of external irradiation. In the second course，the tumor and pelvic lymphatic drainage area were given a conventional fractionated dose of 40 Gy in 20 fractions. The patients treated with conventional IMRT （46 Gy/23 fractions）in cervical mass and pelvic lymphatic drainage area were regarded as control group. After the external irradiation, intracavitary radiotherapy was given. The primary endpoint was hemostasis effect. The secondary endpoints included adverse events（AEs），local contral（LC）rate and overall survival（OS）rate. Results Median follow-up was 48 months. The effective hemostasis rates in the SIB group and the control group in one week were 100% and 40%，respectively.There were no statistically significant differences in LC rate，OS rate，or acute and late AEs between two groups. Conclusion SIB-IMRT is effective and safe for bulky cervical cancer patients with bleeding, which can be selectively used in suitable patients.