The invention discloses a spatial light modulator-based dual-beam optical tweezers system. The system includes a laser, a first telescope system, a half wave plate, a first reflector, a spatial light modulator, a quarter-wave plate, a focusing lens, a second reflector, a second telescope system, an objective lens and a sample stage which are arranged sequentially along an optical path, wherein the half wave plate is used for adjusting the ratio of horizontal polarized light and vertical polarized light in a received beam, the first reflector is used for reflecting the received beam to a corresponding modulation area on the spatial light modulator, and the spatial light modulator is provided with two modulation areas loaded with different phase image information; the beam is subjected to phase modulation once, and then, the phase-modulated beam passes through the quarter-wave plate and the focusing lens, and thereafter is reflected by the second reflector; the reflected beam passes through the focusing lens and the quarter-wave plate again, and arrives at the other modulation region of the spatial light modulator, and thereafter, passes through the second telescope system and the objective lens sequentially, and arrives at the sample stage. With the spatial light modulator-based dual-beam optical tweezers system of the invention adopted, the application range of the optical tweezers can be greatly extended, and experiment accuracy can be improved.