Composite guidance mode can realize better aircraft control than single guidance mode. However, trajectory wreck and attitude change are inevitable during handover from midcourse guidance to terminal guidance, leading to unpredicted control failure. How to realize smooth handoff is of crucial importance to robust control. Focusing on the problem, an effective method using linear factor to realize smooth transition between the midcourse and terminal guidance for the helicopter-borne aircrafts is proposed in this paper. In accordance with the strict constraint conditions of smooth handover, the application scope of the proposed method is analyzed. The effectiveness of the proposed method has been verified on simulated experiments.