Abstract: The performance of the inward-turning inlet is mainly determined by the axisymmetric basic flowfield. Using the ICFA (internal conical flow A) flowfield outlet as the initial boundary and specifying the pressure gradient distribution along the compression surface, a new basic flowfield combining ICFA and pressure gradient was constructed by the method of characteristics. The shock wave at the leading edge of the new basic flowfield was nearly straight, and the compression surface was continuous and smooth with no expansion waves. The results show that the wall pressure along the boundary-layer correction of basic flowfield is completely consistent with the flowfield of method of characteristics, and the reflected shock wave is dissipated at the shoulder point of the compression surface, resulting in good flowfield uniformity downstream. The inward-turning inlet achieves full flow capture at the design point of Ma=6, and the transverse thickness of the flowfield boundary layer along the inlet is uniform, and there is no obvious vortex in the internal compression section.