In this work, the problem of collision detection of bloody particles and soft tissue organs in virtual surgery system was studied. The problem of collision detection between bloody blood and soft tissue in virtual surgery is different from that of traditional rigid body or software collision detection. The topological structure of bloody model changes greatly. The traditional method of collision detection by updating topology cannot ensure real-time and accuracy. A collision detection algorithm for bloody particles and software based on space partitioning is proposed, which can handle collision detection between software based on Smoothed Particle Hydrodynamics (SPH) simulation and software simulated by any dynamic model. At the same time, the uniform space grid established in the nearest neighboring particle search of SPH algorithm is proposed to be reused. The space grid is used for the space division of collision detection and the localization of fluid particles, thus reducing the time and space resources repeated consumption. Experimental results show that the algorithm can meet the accuracy and real-time requirements of collision detection between bloody particles and software in virtual surgery.