激光的本质是微观粒子的有序运动，而热是微观粒子的无序运动，高能激光产生过程中这一对矛盾贯穿始终，可以说高能激光的发展史，就是一部与废热的斗争史。回顾高能激光发展的六十年，剖析高能激光的科学内涵，我们大致将其划分为前后三十年的两个阶段，前一阶段着重解决能用的问题，后一阶段重在解决好用的问题。围绕产热、散热，我们剖析了激光功率、光束质量、效率三者之间的内在关联，简要回顾了各类高能激光器的发展历程，评价了各类高能激光的特色，展望了高能激光未来的发展路径。

Ordered motion of quantum particles produces laser, while disordered motion produces heat, this conflict overwhelms development of high energy laser since its beginning, and the guide-line of its history is just a battle with waste heat. Reviewing the 60-year development of high energy laser and examining the science behind it, we divided its history into pre and past 30 years, which separately solved the problem of capability and was just solving the problem of easy-to-use ability. Sticking with heat generation and dissipation, we discussed inner links between power, beam quality and efficiency of high energy laser, reviewed the rise and fall of different kinds of lasers, and predicted future development of high energy laser.