Maximum range is not only an important index of pulse laser radar,but also a comprehensive reflection of its ranging performance.Based on the ranging equation of pulse laser radar,this paper analyses the factors affecting the maximum range,and gives briefly the considerations in the design of the maximum range.From the point of view of engineering practice,the advantages and disadvantages of current detection methods of pulse laser radar are analyzed,and the fast estimation methods of maximum range are given according to different conditions.These estimation methods are based on engineering practice,and have the advantages of less calculation,low cost,intuitive results,convenient and flexible application.These estimation methods can better guide users to carry out performance testing,maintenance evaluation and other work,and have a high application value.