乾隆时期烟瘴广布云南广西边境地区,清王朝在西南边防上采取消极防御政策,很大程度上是受烟瘴这一客观因素的影响所致。乾隆皇帝曾试图采取积极的边防政策,但终因烟瘴的制约而放弃。消极保守成为清代西南边防的主要策略。 In the Qianlong period, where soot was widely distributed in the border area of ​​Yunnan and Guangxi, the Qing Dynasty adopted a passive defense policy on the southwest border and was largely affected by the objective factors of sootiness. Emperor Qianlong tried to take an active border policy, but eventually gave up because of the restrictions imposed by it. Negative Conservatism Becomes the Main Strategy of the Southwest Frontier Defense in Qing Dynasty.