A Triaxial Improved Hybrid A* (TIH-A*) algorithm is proposed for the trajectory planning problem of aerospace vehicle in the Terminal Area Energy Management (TAEM) phase under the influence of non-circular restricted airspace. According to the trajectory generation mechanism of the algorithm, the flight trajectory is divided into a Hybrid A* segment generated by searching and a Dubins segment generated by geometric splicing. For the Hybrid A* segment, a potential function is introduced to modify the cost map to reflect motion trends and safety constraints; child nodes are expanded based on angle-of-attack and bank angle commands to reflect dynamic constraints; a cost function describing the terminal predicted altitude error is designed to reflect terminal constraints; and an adaptive node exploration logic is proposed to improve the adaptability of the algorithm. For the Dubins segment, a nonlinear lateral guidance law is designed based on heading angle error to improve trajectory tracking performance. A longitudinal guidance law is proposed, which corrects the dynamic pressure profile in the inner loop and the predicted flight path angle in the outer loop. Simulation results under various scenarios show that the proposed method can effectively achieve no-fly zone avoidance and trajectory planning in the TAEM phase under non-circular restricted airspace. The generated trajectories have high design accuracy and good adaptability to mission parameters and flight scenarios.