The invention relates to a self-adaption coupling system for a single mode optical fiber based on two-dimensional scanning of the optical fiber end surface. The self-adaption coupling system comprises a rapid tilting reflection mirror, a coupling lens, an optical fiber end surface positioning device, a single mode optical fiber, 1*2 optical fiber branching device, a photoelectric detector, a control platform and a multi-channel high-voltage amplifier. According to the self-adaption coupling system, the efficient and stable coupling efficiency of space light and the single mode optical fiber is guaranteed; the optical fiber end surface positioning device is utilized for controlling the optical fiber end surface so as to realize the two-dimensional scanning of focused light spots, and the change rule of the power of light output by the optical fiber is monitored so as to calculate the optimization gradient of the coupling efficiency; and the rapid tilting reflection mirror is combined with an optimization algorithm, so that the self-adaption capturing tacking of the optical fiber end surface to the focused light spots is finished. The self-adaption coupling system has the innovation points that the optimization gradient detection is realized by virtue of the two-dimensional scanning of the optical fiber end surface to the focused light spots; the optimization gradient detection is separately executed with an iteration calibration process, so that the self-adaption coupling system has the advantages that the bandwidth availability ratio of a device is high, the Motion inertia is small, the tracking precision is high, the structure is compact, and the like; and the self-adaption coupling system has important application prospects in the communication field of space light.