With the advancement of robotics technology, bipedal robots have become a key research focus in the field of intelligent robotics. To enhance their locomotive performance and environmental adaptability, existing studies have integrated thrusters into bipedal robots,which are intended to provide assistance. In this paper, we constructed the walking dynamics model of bipedal robots under the influence of external force fields realized by thrusters. A posture adjustment control strategy is also proposed for bipedal robots, which is used to control the pitch angle and yaw angle of the robot. Additionally, we quantitatively analyzed how external force fields of different magnitude and directions affect key performance metrics of bipedal robots, including lower limb joint torques, overall power consumption, and energy efficiency. Simulation results indicate that the thruster-generated external force field can play positive effects for posture adjustment and overall power consumption optimization of bipedal robots.