In order to study the influence of liner thickness and grid number on the reliability of numerical simulation of a big bore shaped charge warhead, the nonlinear dynamic finite element software AUTODYN was used to simulate the process of single-cone liner jet formation and penetration into 1 000 mm thick steel target with an aperture of 140 mm, and the static penetration test was carried out. By dividing the grid number of liner wall thickness into five schemes, the influence of grid number on the formation and penetration of single-cone liner jet was investigated.The results show that when the grid number is small, the jet breaks in advance and the penetration depth is low, and there is a big gap with the experiment; when the grid number of liner wall thickness is n = 6 and 7, the results are most consistent with the experiment results.