The previous data interpretation equation for medium and low stress is no longer applicable when in-situ tests are carried out in deeply seated soils. In order to explore the mechanical properties of sand under high stress conditions, in this paper, the cone penetration test in silica sand with different relative densities and confining pressure levels was performed in a self-developed high-pressure calibration chamber, and the Arbitrary Lagrangian-Eulerian method, a large deformation finite element approach, was used to study cone penetration in silica sands. Frequent mesh generations were conducted to avoid the distortion of soil elements around the cone tip. A modified Mohr-Coulomb constitutive model was introduced to describe the internal friction and dilatancy angle varied with the plastic shear strain in silica sands. A method for determining shear modulus by correcting the bending element tests was proposed. Numerical results of cone tip resistance agree reasonably well with calibration chamber tests. An empirical equation for cone tip resistance varied with different relative densities was established under high stress condition, and the comparison with the existing low stress test results show that the established equation can predict well the relative density of sand by the cone tip resistance.