Objective To conduct a multidimensional effectiveness evaluation of the simulated vaginal operative delivery training program conducted in the Department of Obstetrics and Gynecology, Peking University First Hospital, based on Kirkpatrick's four-level evaluation model and the Diffusion of Innovations Theory, and to provide evidence for optimizing obstetric operative training. Methods A questionnaire survey method was employed. A total of 96 participants from 5 training sessions conducted from May 2022 to May 2024 were included in the study. Data were collected through questionnaires and one-year post-training follow-ups to evaluate training effectiveness from the three dimensions (reaction, learning, and behavior) of Kirkpatrick's four-level evaluation model. The Diffusion of Innovations Theory was introduced to describe the collective impact triggered by the training. Data were described using mean scores, numbers, and percentages. Results Reaction level: The average satisfaction scores ranged from 19.3 to 19.7 (out of 20), all indicating ″very satisfied″. Learning level: The intended clinical application rates for the four courses, from highest to lowest, were forceps delivery simulation [89/96 (92.7%)], vacuum extraction simulation [80/96 (83.3%)], forceps technique [74/96 (77.1%)], and vacuum extraction technique [59/96 (61.5%)]. Behavior level: One year post-training, 41 participants were followed up; 29 (70.7%) had applied the learned techniques. Forceps delivery was most applied [23 (79.3%)], followed by vacuum extraction [6 (20.7%)]. Of these, 28 (96.5%) performed their first procedure within 0-3 months post-training. Furthermore, 32 (78.0%) reported significant improvement in procedural standardization. Regarding collective impact, the training program demonstrated positive diffusion effects on clinical practices across 10 participating hospitals, showing potential for regional practice improvement. Conclusions The training program achieved high satisfaction and significant knowledge/skill improvement, with high and timely behavioral transfer, especially for forceps delivery. Using the Diffusion of Innovations Theory as a complementary framework effectively describes the diffusion of trained behaviors from individual mastery to group practice, laying a foundation for future evaluation of long-term organizational benefits.