The objective of this research is to optimize the cross-sectional shape of an Averaging Pitot Tube (APT) flow sensor with Flow Conditioning Wing (FCW). The flat cutting and circle cutting wingtip shapes were researched through Computational Fluid Dynamics (CFD) simulation and air flow experimental tests for two different cross-sectional shapes of the APT flow sensor. The results show that the flat cutting wingtip shapes are better than the circle cutting, the wingtip width or wingtip arc radius of 0.3 mm are better than 0.5 mm, and the circumscribed circle diameter 8 mm is better than 6 mm as the cross-sectional shape is the same. Flow field analysis indicates that the wingtip shape determines the position of fluid flow separation, so affects the shape of the vortex area downstream of the detecting tube. The ratio of vortex width and length can express the vortex shape. The experimental data show that the smaller the ratio, the better the linearity and the repeatability of the sensor.