The opposing jet flow significantly alters the aerodynamic characteristics of the rocket body during the power deceleration process of the recoverable rocket. In order to obtain the influence of the opposing jet flow on the aerodynamic characteristics of the rocket body, the lift-drag coefficient of the rocket body is obtained by numerical simulation method. The change law of the lift-drag characteristic is analyzed and the representative parameters of lift-drag characteristic are propsed. Firstly, the numerical simulation of the opposing jet of blunt body was carried out, and the obtained results were compared with the published experimental data to verify the effectiveness of the numerical simulation method. Secondly, the RANS method was used to simulate various typical flight states of single-nozzle configuration rockets. The lift-drag coefficient of the rocket body changed with the angle of attack and the change law of lift-drag characteristics were obtained. The lift-drag characteristics were obtained by analyzing the flow state in the recirculation zone. Finally, the representative parameters are proposed according to the degree of influence of the opposing jet on the aerodynamic characteristics of the rocket body. Research findings indicate that the opposing jet forms a shielding effect on the rocket body and affects the lift-drag characteristics. In the presense of opposing jet, the lift-drag characteristics are greatly affected by the flight height, while the effect of flight Mach number is relatively minor, which is opposite to that observed without the opposing jet. The drag coefficient is less than 0.1 in most flight conditions, and negative drag may occur in some high-altitude flight conditions. To characterize the aerodynamic effects of the opposing jet on the rocket body, a parameter is proposed that represents the ratio of the opposing jet width to the rocket body width. This parameter effectively reflects the shielding effect of the opposing jet on the rocket body and characterizes the variations in its aerodynamic characterics of the opposing jet.