This paper studies the equivalent modeling method of truss cell elements with clearance joints. The equivalent stiffness and damping problem of unit cell truss are mainly considered. Firstly, a comprehensive hinge gap model is constructed by considering on the gap hinge. An equivalent method is then put forward to simplify the truss unit cell to a plate?like structure. As structural element is assumed as a steel beam, the displacement method is used to get the equivalent stiffness matrix of plane truss unit cell in different boundary condition. The overall natural frequency and plate equivalent stiffness matrix after equivalence are then obtained. Finally, finite element analysis (FEM) by a software of ANSYS is proposed for structural modal analysis of the structure with clearance joint. The results show that when the stiffness of the truss structure unit cell is reduced, the flexibility is increased.