| The finite particle method (FPM) is based on vector mechanics. In this method, a finite number of particles calculated by Newton's law of motion are used to simulate the deformation behavior of the structure. In FPM, the particles are connected by the components, which restrict the motion of the particles, and the internal force of the component is described by the motion variables of the particles. Based on the basic idea of vector mechanics and nonlinear beam theory, a novel FPM is proposed in this paper. In this method, the nonlinear deformation of the beam is described in the co-rotational element coordinate system. Taking the spatial beam structures as an example, the nonlinear formulas of calculating the internal force of the component are derived, and the bending and twist coupling deformation is considered. The rotation matrix of co-rotational element coordinate system is obtained by the transformation formula of two successive Euler angles. Compared with the traditional FPM, the proposed method avoids the analysis of rigid body virtual rotation. Numerical solutions are presented for four structures, which indicate that the present FPM algorithm is highly accurate in predicting large deformation responses of structures.