To solve the problems of the existing virtual human simulation technology in the ship's narrow space maintenance operations, such as the inefficiency, the need for many manual interventions, and the high cost of simulation, a virtual human posture hybrid modeling and simulation technology was proposed. According to the characteristics of human body maintenance operations in a narrow space, the virtual human posture modeling was divided into two parts:virtual human torso and lower limb posture modeling and virtual human arm posture modeling. Firstly, a narrow space automatic posture matching algorithm based on the posture library was proposed to determine the operation position and posture of the virtual human in narrow space. On this basis, a multi-objective optimization model was established to solve the arm posture and realize the maintenance simulation posture generation. Experimental results with a certain type of ship engine room tank valve maintenance as an example show that the proposed method can realize the automatic positioning and generation of virtual human posture, and can effectively improve the efficiency of maintenance simulation.