A method and a device for measuring light field distribution are provided; including steps of utilizing the optical trap to stably levitating particles, moving the optical trap to bring the particles close to the light field to be measured, and utilizing the photodetector to collect the scattered light signals of the particles at different positions in the three-dimensional space of the light field to be measured, and calculating the light field distribution of the light field to be measured according to the scattered light intensity which is proportional to the light intensity at that position. The device for measuring the optical field distribution includes a laser, an optical trapping path, particles, a photodetector, a control system and an upper computer; the laser emits a laser, passes through the optical trapping path, and emits highly focused captured light B to form an V optical trap to capture particles.