Finite element model of hexagonal honeycombs cell arrays was established. The out-of-plane impact performance of hexagonal metal honeycombs was studied by using finite element method. When all configuration parameters of hexagonal metal honeycombs were kept constant, under different impact velocities, dynamic compression test was simulated to study the influences of wall thickness on out-of-plane impact performance of hexagonal honeycombs. The formula to calculate the out-of-plane plateau stresses of hexagonal aluminum honeycombs was been given based on the finite element analysis results.