Objective To explore the effect of 3D animation simulation of normal electrocardiography (ECG) and ventricular hypertrophy ECG waveform in diagnostic ECG teaching. Methods From November to December 2021, a controlled experimental design was employed. Animation software and computer 3D modeling were utilized to simulate the process of forming normal and ventricular hypertrophy ECG waveforms from their respective 3D vector rings, which underwent ″secondary projection.″ These animated lectures were then applied in the teaching of diagnostic ECG, and the teaching outcomes were evaluated subsequently. Students from the seven-year traditional Chinese medicine program at Zhejiang Chinese Medical University in 2019 were randomly selected; 30 students were assigned to the study group, which received instruction using 3D animated ECG waveform lectures, while another 30 students from the seven-year acupuncture and tuina program were designated as the control group, undergoing traditional theoretical teaching. Following the teaching sessions, the effectiveness was assessed through theoretical exams, ECG interpretation exams, and questionnaires. Independent sample t-tests were performed to analyze the data. Results The study group achieved higher scores than the control group in both the theoretical ECG exam [(7.47±0.97) vs. (6.90±0.89),] and the ECG interpretation exam [(6.83±0.83) vs. (6.23±0.68)], both P<0.05. Additionally, the study group received higher ratings than the control group in terms of enhancing the interest in ECG knowledge [(7.97±0.77) vs. (7.37±1.07)] and invigorating classroom atmosphere [(7.40±0.77) vs. (6.90±0.92)] and so on, all P<0.05. Conclusions The use of 3D animation visualization technology to simulate normal and abnormal ECG waveforms in the teaching of diagnostic ECG has proven to yield favorable teaching outcomes.