Objective To investigate the application effects of a modified Peyton teaching method based on SOAP assessment in the pediatric development evaluation instruction for undergraduate students in the field of rehabilitation therapy. Methods An experimental control method was employed. A total of 40 undergraduate students enrolled in 2020 and 2021interning in Department of Rehabilitation, Xinhua Hospital Affiliated to Shanghai Jiaotong University School of Medicine from 2023 to 2024 were enrolled in the study. Among them, 20 students from 2024 were assigned to the experimental group and received the modified Peyton teaching method, while 20 students from 2023 were assigned to the control group and received the traditional teaching method. Both groups were assessed with knowledge and practical exams, as well as a questionnaire survey within week after the completion of the teaching, to evaluate the effectiveness of the two teaching methods. Statistical analysis was performed using t-tests, nonparametric tests, and chi-square tests. Results Comparison of examination scores showed that the experimental group's theoretical examination scores were 95 (16) and practical examination scores were (88.23±5.02), which were both higher than the control group's knowledge examination scores of 87 (11.75) and practical scores of (83.05±4.26), with statistically significant differences (both P<0.05). The questionnaire survey results indicated that the experimental group's improvements in operational skills, clinical reasoning ability, communication skills, learning interest, and subjective initiative were all significantly higher than those of the control group, with statistically significant differences (all P<0.05). Conclusions The modified Peyton teaching method based on SOAP assessment is beneficial for improving the theoretical knowledge and practical skills of pediatric development evaluation among undergraduate students in rehabilitation therapy, enhancing the effectiveness of their internship experience.