Liver has complex biomechanical properties. Therefore, it is difficult to achieve real-time requirement because of the large amount of calculation in deformation simulation. At the same time, it is inaccessible to achieve the reality in real-time simulation of liver deformation. In order to solve this contradiction, a hybrid model which can automatically change the operating area and force of surgical instruments is developed. According to theoretical analysis, a construction method for the mesh and meshless model of liver is proposed. The experimental results show that the algorithm has high computational efficiency and good deformation effect, which can meet the realistic and real-time requirements of virtual liver surgery simulation. The conclusions drawn in this paper can be used to guide the study of virtual liver soft tissue surgery.