普通弹丸的底阻约占弹丸总阻的1／3。因此，准确测量底阻是准确测定弹丸总阻的关键。在超音速风洞中进行测力实验时，模型底部大多用一根天平支杆将模型支撑在风洞中。由于尾支杆的存在，使得模型底部流动发生畸变，引起底阻测量的不准确。本文介绍了天平尾支杆和模型船尾角对超音速弹丸底压测量的影响。研究表明，尾支杆直径从小到大变化时，底压经历了一个由大到小，再由小到大的过程；在一定的范围内船尾角起到提高底压的作用。 Ordinary projectile base resistance about Projectile total resistance of 1/3. Therefore, accurately measuring the resistance is the key to accurately measure the total resistance of the projectile. In supersonic wind tunnel in the force test, the bottom of the model mostly with a balance brace to support the model in the wind tunnel. Due to the existence of the tail boom, the flow at the bottom of the model is distorted, causing the inaccuracy of the bottom resistance measurement. This article describes the effect of the tail end of the balance and the model stern angle on the measurement of supersonic projectile pressure. The results show that when the diameter of the tail boom varies from small to large, the base pressure experiences a process from small to large, and then from small to large. The stern angle plays a role of increasing the base pressure within a certain range.