The principle of optical rotation due to the transfer of spin angular momentum from light to particles was discussed by analyzing the interaction between the beam of light and birefringent crystal particles. Through MATLAB simulation, the dependence of the rotation frequency of the trapped particle on the laser power was analyzed, it was obtained that the rotation frequency was proportional to the laser power. The birefringent different particles were rotated by the optical tweezers, the wavelength of He-Ne laser was 632.8 nm, at the same time the rotation frequency was measured, and the maximum speed could reach 5 r/s. The dependence of the rotation frequency of the trapped particle on the laser-power was experimentally studied for several birefringent particles with different sizes in the optical tweezers. When experimental results were compared with theoretical results, experimental results and theoretical analysis were agreeing very well, and the reasons for the error were analyzed, which the bottom friction affected the most.