Abstract: The abnormity of the axial-symmetric boundary in simulation of shock-induced combustion was discussed.Practice has shown that the abnormity(distortion of combustion front) may appear near the axis when the velocity was below the detonative speed.Four key factors,such as the solution method of the boundary,numerical scheme,chemical reaction model and mesh were analyzed.It is shown that all factors can cause the abnormity,but the numerical scheme should be the most fundamental one.The abnormity may be similar to the‘carbuncle' problem.Some reasonable measures are proposed,and numerical results show the availability of these proposals.