A complete hospital security system is essential for the life and property safety of medical workers, patients and their families alike. The successful operation of the system depends on a reasonable staffing of the security department.From 2019, a tertiary hospital has explored and practiced the staffing management of security guards based on the actual needs of the hospital. The first job was to classify its security posts setup, and determine the staffing requirements of front-line security posts based on such indicators as scale, risk and people flow. The management range theory was called into play, to set the staffing coefficient of front-line security posts and their corresponding frontline administrators as 7∶1, and set that each management post needs one middle manager. The next job was to calculate the number of security guards per workload/post. The calculations estimated that the number of guards required for the four front-line security posts, namely, gate keeper post, public area patrol post, security and fire control post, and emergency response unit post, was 37, 46, 26 and 26 respectively. The corresponding management posts, namely, the office of the security department, the security management team, the fire management team, and the order maintenance team, required 7, 8, 5 and 5 management personnel respectively, totaling 160. Based on the calculations, the hospital optimized its staffing, and increased its total security personnel from 150 to 160, including the number of gate keeper posts were reduced by 17, and the number of emergency response unit posts was increased by 22. This optimization has effectively empowered the security department in dealing with medical disputes and emergencies, as well as identifying fire hazards, which serves a reference for the rational staffing of hospital security human resources.