<p>This paper investigates a penetrating evading strategy in the aircraft guidance or collision avoidance area, involving one agile evader and three identical weak pursuers in three-dimensional space. In high-speed encounter scenarios, the game could be simplified to a game that occurs in a two-dimensional space with a fixed terminal instant. The initial topology of the three pursuers’ zero-effort coordinates is considered as an equilateral triangle in this paper. The recent studies often adopt the reachable set method for some multi-player differential games, and this paper aims to achieve a bigger terminal miss by presenting a two-step evading strategy for the evader, with actions being designed only at two critical time points. There are three ingredients: Firstly, we present an analytic solution for a two-step strategy based on a singular case, and its correctness is validated via a numerical optimization algorithm; Secondly, we compute the optimal initial triangle for achieving the lowest bound of the terminal miss, under the proposed evader’s two-step strategy; Thirdly, we compare the proposed method and reachable set method, and the results show that the terminal miss increases by about four percent.</p>