Abstract: A rapid trajectory planning method of collision avoidance and obstacle avoidance is proposed to address the problem of landing on irregular small celestial body. An analytic form of landing trajectory is constructed using Bézier curve, and the collision avoidance and obstacle avoidance schemes are proposed. The guiding point of collision avoidance is set to prevent occlusion from the small celestial body, and the guiding point of obstacle avoidance is set to ensure landing along the normal direction of the landing plane. Considering the geometrical relationship between the lander and the small celestial body, and the monotonicity of height of the guidance point, constraints are established for the parameters of the collision avoidance point and the obstacle avoidance point. Under these constraints, the parameters are rapidly solved with the objective of combustion consumption. Additionally, the minimum landing time is investigated, with the thrust constraint determining the feasible range of landing time. Finally, the proposed trajectory planning method is simulated in a landing scenario of 433 Eros. Results show that the planned trajectory satisfies the constraints of collision avoidance, obstacle avoidance, and thrust control under various initial conditions, while maintaining high computational efficiency.