A device of optical tweezers array based on double-plate shearing interference and its application to separating polystyrene particles are studied. The technique is hopeful to be a novel method of particle separation, such as cells. Firstly, the classical optical tweezers theory is modified to set up theoretical model of optical tweezers array system. The parameters of the model are discussed and simulated by Matlab software to provide the theoretical foundation for the following device design. And an optical tweezers array is set up based on the parameters. With adjusting the angle between two interference fields, a two-dimensional optical tweezers array which has different distribution characters can be obtained. By applying the system to particle trapping, 6 μm polystyrene particles are trapped successfully, which proves the rationality and feasibility of the design.