Abstract:The environmental knowledge of farmers was divided into system knowledge, action-related knowledge and effectiveness knowledge. Based on the investigation data of 498 tea growers in the Qinba mountainous area, the study examined the direct impact of environmental knowledge on households’ environment-friendly behaviors, and the indirect impact of environmental knowledge on environment-friendly behaviors by changing households’ environmental capabilities through the bootstrap method. It also verified the moderation effects of social norms on environmental knowledge and environmental capabilities affecting households’ environment-friendly behaviors. The results showed that: social norms have a significant positive moderation effect in the process of system knowledge directly affecting households’ pollution reduction behaviors, and the process of action-related knowledge directly affects households’ pollution reduction behaviors and environment improvement behaviors. Environmental capabilities play a positive mediating role in the process of action-related knowledge affecting households’ reduction pollution behaviors and environmental improvement behaviors. The moderating effect of social norms in the process of action-related knowledge affecting households’ pollution reduction behaviors and environment improvement behaviors through environmental capabilities is positive. So,the government should comprehensively improve the environmental knowledge and environmental skills of farmers, and shape pro-environmental social norms.