The falling of a biped humanoid robot is treated as an extremely unstable state. When an unexpected fall happens, it may cause serious damage to both the robot itself. This study focuses on the falling issue and investigates the effect of the 'torso protective strategy' for safe landing of a biped humanoid robot. First, the effectiveness of the torso strategies to the safe landing is analyzed from an energy variation perspective of the robot system. The torso strategies are used to do negative work that reduced the energy of the robot system, thereby reducing the impact velocity of the robot. Then, a comparative simulation is made on a model of humanoid robot to validate the influence of the torso strategies on safe landing.