Objective：Through operation analysis of the department of thyroid and breast surgery in a third-level general hospital under the new situation of medical reform, this paper discusses the lean management of hospitals. Methods: To investigate and analyze the operation status of the department of thyroid and breast surgery in a third-level hospital, including workload, operation efficiency, profit and loss, etc. Results: There are many outpatients, inpatients and ultrasound examination patients in the department of thyroid and breast surgery, and the workload of doctors is heavy. It is calculated that two clerks are needed to be added in this department; through the profit and loss analysis, it shows that the department of thyroid and breast surgery is a Taurus department, and the utilization rate of the bed is high. The scale should be appropriately expanded to additional 10 beds. Conclusion: Through detailed operational analysis of all departments of the hospital, decision-making basis can be provided for hospital administrators and managers and the lean management of the hospital will be realized.