Objective To observe the effectiveness of prevention and management of venous thromboembolism (VTE) in the day surgery wards, analyze the influencing factors of VTE occurrence in postoperative patients, in order to reduce the occurrence of VTE adverse events, improve the utilization of medical resources, and enhance the quality of day care. Methods The patient data of the Daytime Diagnosis and Treatment Center of Deyang People’s Hospital between January 2020 and December 2023 were retrospectively selected. According to the implementation time of VTE prevention and control in the day surgery wards, patients between 2022 and 2023 were selected as the observation group, and patients between 2020 and 2021 were selected as the control group. The incidence and the influencing factors of postoperative of VTE were compared between the two groups. Results A total of 2 300 patients were included, with 1 150 cases in each group. The comparison of in-hospital [12 cases (1.0%) vs. 3 cases (0.3%)] and post discharge [7 cases (0.6%) vs. 1 case (0.1%)] VTE incidence rates between the control group and the observation group showed statistically significant differences (P＜0.05). Among the 9 specialties in the Daytime Diagnosis and Treatment Center, the incidence of VTE in thoracic surgery (1.58%), vascular surgery (1.51%), and hepatobiliary surgery (1.29%) ranked among the top 3. The results of multiple logistic regression analysis showed that fourth grade surgery, lower limb surgery, and large intraoperative bleeding (>100 mL) were the influencing factors for postoperative VTE (P<0.05). Conclusions There are many reasons for VTE occurrence, and it is necessary to prevent and treat VTE in the day surgery ward. More attention should be paid to the patient’s surgical grading, intraoperative bleeding volume, and surgical site.