Concerning the problem that the sliding mode guidance law with terminal angle constraint has too large an acceleration command at the initial stage of guidance process, an angle constraint guidance law considering acceleration constraint is designed using the reaching law method and a damping term. The relationship between the magnitude of the acceleration command and the approaching speed of the sliding mode variable is analyzed first. Then, a damping term is introduced into the sliding mode surface function to dynamically adjust the proportion of different parts of the guidance instruction, thereby reducing the overall instruction value at the initial stage of the guidance process. Finally, a multi-power adaptive reaching law is designed to adjust the approaching speed of the sliding mode variable at different stages to reduce the extreme value of the guidance instruction and meet the acceleration constraint. The fast convergence of the sliding mode surface function is guaranteed in the meantime. Compared with the common terminal-angle-constrained sliding mode control-based guidance law, the simulation results demonstrate the effectiveness of the proposed guidance law in reducing acceleration command extremes.