The active evasion strategy of spacecraft is discussed when the distance between spacecraft and target is relatively short. Firstly, the relative dynamic model is analyzed. The relative motion can be decomposed into two submotions, viz., the relative motion in the instantaneous rotation of the line of sight (IRPL) and the rotation of this plane. Secondly, the optimum evasion direction of the spacecraft is proposed, through the analysis of the relative motion in IRPL. Thirdly, the determination of this direction in the inertial space is discussed. Finally, the numerical simulation is conducted with different maneuver accelerations and different detective distance of the spacecraft. The effectiveness of the active evasion strategy is demonstrated with the simulation results.