Objective To evaluate the effect of three-stage simulation teaching in clinical practice of general ICU for undergraduate nursing students. Methods In synchronous clinical practice of critical care, 27 undergraduate nursing students was taught using three-stage teaching based on simulated case:theory learning-case simulation drill-clinical practice. After 4 weeks teaching, the teaching effect was evaluated using the Simulation Teaching Evaluation Scale, simulation teaching feedback questionnaire and clinical practice evaluation. Results Students′evaluation score on simulation design, educational practices in simulation, learning satisfaction and self-confidence in general ICU were over 4 out of 5. All students were interested in the three-stage simulation teaching, they thought case simulation was very helpful for their ICU clinical practice. ICU clinical teachers′ evaluation score on students′ clinical practice was 96.07±1.96. Conclusion Conducting the three-stage simulation teaching for undergraduate nursing students in clinical practice of general ICU is conducive to improving teaching effect and clinical practice effect.