The traditional agricultural production mode in Nanmang County can be divided into paddy rice farming in dam area and knife-and-burn farming in mountain area. After the 1950s, the state began to carry out all-round transformation of agriculture, the traditional agricultural farming mode has changed. Especially in mountainous areas, the change of agricultural mode represented by slash-and-burn cultivation is the most obvious, which has caused a great impact on the ecology. The author will sort out the operation mechanism and ecological knowledge of slash-and-burn agriculture as a kind of traditional local knowledge, and show the cognition and adaptation of people to nature in the traditional period. <<