Shipborne laser weapon is an effective, fast and low-cost defense against drone swarms. In this paper, aiming at the countermeasures of ship drone swarm, the damage mechanism of shipborne laser weapons to drones of different materials is analyzed. Firstly, combined with the laser damage threshold of drone materials, a laser weapon countermeasure drone swarm model is established. Then, the effective striking distance of drone swarm under different laser power conditions is simulated, and the combat effectiveness of laser weapons against drone swarm is evaluated and analyzed finally, which can provide support for the subsequent laser weapons coordinated fire against UAVs.