The invention discloses a brick and concrete block separation device design method based on a computer simulation and assembly technology, and the method comprises the steps of firstly obtaining the parameters of materials and equipment, including the material density, the particle shape, the internal friction angle, the suspension speed, the elasticity modulus of the materials and the equipment,and the friction coefficient; using a computer particle discrete element and fluid simulation coupling technology for realizing the movement rule of the material in the separation process to thereby optimize the working parameters of the separation equipment; completing the simulated installation and debugging of the equipment parts through the virtual assembly technology, and finally machining and testing of the entity equipment. The design method is visual and traceable, and the design process is well documented.