The relation between ground distortion and instantaneous field of view of the imaging system was analyzed; variable-speed scanning imaging was proposed and angular scanning speed formula was derived with infrared zoom scanning imaging system of super-swath low distortion in space as research object in this paper. Meanwhile, a kind of rapid fly-back method of sine acceleration was designed to solve the shortcomings such as low scanning efficiency of uniform 360° rotation, scanning line appliance needed to be installed for two-way swing scanning imaging and high complexity and low reliability of the system. Simulation and experiments were conducted on variable-speed scanning and rapid fly-back method of sine acceleration in this paper and the result indicates that the state shift between slow scanning and rapid fly-back of scanning control system is stable and the start and stop angle error of scanning is just 1.44 arc-second; scanning speed stability is ±0.5%; time error in scanning imaging process is 83 μs and fly-back time error is 250 μs; time deviation of the whole scanning period is less than pixel integral time (355 μs) and scanning efficiency reaches 86%, thus scanning efficiency is improved and impact and vibration of scanning mechanism are reduced meanwhile to satisfy imaging requirements. Rapid fly-back method of sine acceleration will provide a reference for rapid fly-back motion design of airborne infrared scanning imaging system.