We propose a method to solve nonlinear second-order cone programs (SOCPs), based on a continuously dierentiable exact penalty function. The construction of the penalty function is given by incorporating a multipliers estimate in the augmented Lagrangian for SOCPs. Under the nondegeneracy assumption and the strong second-order sucient condition, we show that a generalized Newton method has global and superlinear convergence. We also present some preliminary numerical experiments.