The work aims to analyze the mechanical properties of the brazed high temperature alloy honeycomb sandwich panel under the high-speed impact of projectile. The dynamic response and failure of the honeycomb sandwich panel under different impact strength were studied through the light-gas gun test combined with FE simulation. The lateral compression experiment of the honeycomb sandwich panel with high-speed impact damage was carried out to study the effect of damage modes on the residual strength of the sandwich panel. Results showed that the impact strength had obvious influence on the failure process and failure mode of the sandwich panel. When the impact strength was not enough to penetrate the front face, the failure mode of the sandwich panel is indentation damage. With the increase of impact strength, different degrees of local core compression appeared. When the impact strength was greater than the critical value, front face and rear face were penetrated, the sandwich panel had intrusion damage and penetration damage. The high-speed impact damage causes the lateral compression failure mode of the honeycomb sandwich panel to change from ideal plastic buckling to local instability, and the limit load of lateral compression is greatly reduced.