The axial force of missile is often negative at high angle of attack during low speed wind tunnel test. The phenomenon is quite different from positive axial force phenomenon during high speed wind tunnel test. The reasons of previous phenomenon have been argued. The reasons will be studied in the paper. The pressure distribution characteristics of missile nose section were studied by pressure measurement test at high angle of attack. The primary reason about negative axial force of missile at high angle of attack and low speed is due to the suction caused by large area negative pressure of missile nose. The effects of Reynolds number on axial force of missile were also studied.