For antimissile, antisatellite, or such kind of strategic defense application, laser weapon is expected to emit 100 kW power or higher level. By considering the development and its object of laser weapon, a new damnification method using multi-mode laser was presented. Using the lasers, different in wavelength, pulsed and continuous wave, frequency verified, focused on target commutatively or synchronously to get more effective result. A complex damnification model was conceived and simulated by using finite element method. A 2 kW continuous wave laser and a long pulse width laser were used in the damage comparison experiments. Both the simulation and experiments results indicate that pulsed laser is better than continuous in metal ablation, furthermore, complex laser is much better. Comparing with pulsed laser, complex laser inspires "nonlinear avalanche ablation" effect, which makes the ablated metal 13 times more than using pulsed laser. This "nonlinear avalanche ablation" effect makes a base for "multi-mode coaxial combined" laser weapon.