Wood friction welding is a green and pollution-free wood processing technology. Research on wood friction welding mainly focuses on the influence of wood type, welding process, and welding interface additives on welding interface strength. However, studies on the tribological properties of wood friction welded interface and its effect on the strength of the welded interface are few. In this article, chemical additives in wood were added to the interface. The frictional force, normal force, microstructure, and chemical composition of the welding interface, and their effects on the strength of the welding interface were studied. In the rotating friction welding of wood, frictional force increased gradually with friction welding. Approximately 2 s after welding, the frictional force achieved a stable state. Normal force increased and then gradually decreased. No considerable changes in frictional force and interface strength were observed and interface strength increased with normal force. The interface strength of glucose and rosin increased, whereas that of N-2 protection showed little change. The interface strength of tung oil, cellulose, and guaiac decreased. This study provides a basic reference for the further industrial application of wood friction welding technology.