Besides the general introduction of sea buckthorn, the processing status of sea buckthorn powder, including processing technology and application status of sea buckthorn powder, is described, which emphatically involves the factors that affect the processing quality of sea buckthorn. The physical basis of immune regulation in sea buckthorn is also discussed, and the nutritional components affecting immunity in sea buckthorn are explained. The effects of sea buckthorn on immune system are summarized. Finally, the product development and the problems and prospects of sea buckthorn powder processing are provided in detail.