Objective: To evaluate the effect of standardized teaching on operational proficiency and complication prevention among young physicians performing outpatient painless gastrointestinal endoscopy. Methods: A total of 100 patients undergoing outpatient painless gastrointestinal endoscopy from January 2024 to January 2026 were included and randomly allocated to an observation group or a control group, with 50 patients in each group. Procedures in the control group were performed by young physicians who received traditional apprenticeship-based teaching, whereas procedures in the observation group were performed by young physicians who received standardized teaching. Procedure-level operational proficiency, complication incidence, patient satisfaction, and post-training theoretical and practical assessment scores were compared between the two groups. Results: Gastroscope insertion time, colonoscope insertion time, and examination completion time were significantly shorter in the observation group than in the control group, and the number of procedural errors was significantly lower (all P < 0.001). The overall incidence of complications was lower in the observation group than in the control group (4.00% vs. 18.00%, P = 0.007). Patient satisfaction was higher in the observation group than in the control group (96.00% vs. 80.00%, P = 0.014). Theoretical and practical assessment scores of young physicians were also significantly higher after standardized teaching (both P < 0.01). Conclusion: Standardized teaching can improve procedural proficiency, reduce complications, enhance patient satisfaction, and strengthen the comprehensive clinical competence of young physicians performing outpatient painless gastrointestinal endoscopy. This teaching model has practical value for clinical training.