Laser weapon is a complex system, which consists of laser, optical system, ATP (Acuisition Tracking Pointing)system, electronic control system and so on. It needs the close cooperation of structure, optics, electronics and other disciplines. Laser weapon has developed rapidly in recent years, and developed countries have increased investment in experiments. Laser weapon has the advantages of high cost-effectiveness ratio and light speed attack. It has been applied in vehicle, shipboard and airborne, and may develop into space application in the future. In recent years, drones play an increasingly important role in the battlefield. Laser weapon is a powerful weapon to deal with drones. Laser weapons can be classified into chemical lasers, solid-state lasers, free electron lasers and so on. Solid state laser will be an important direction of laser development in the future. © 2021 SPIE.