The development of laser weapons needs to consider the technical challenges, battlefield environment, and combat missions. There are many difficulties in promoting the application of laser weapons, such as high energy and high beam quality laser source, long distance fighting, high efficient damage, high compact design, and actual combat. According to the basic physical principles, this paper discusses and put forward five design criteria of the laser weapons, including high brightness criterion, divergence angles matching criterion, maximum of bucket power criterion, high efficient coupling criterion, and platform fit criterion. These design criteria can provide reference for the research and design of laser weapons.