[en] In study of the unit of the tungsten divertor, the effects of different parameters of the unit such as the size of the tungsten target plate, the cooling structure and the flowing parameters of the cooling water are focused on in this paper. The directions of design and optimization of the divertor unit and its cooling structures for both the divertor target plate and the dome are given. In addition, the validation of the performance of the cooling structures is implemented by experiments under high heat fluxes. Finally, the stress and safety of the divertor units under mechanical loads, high heat loads and electromagnetic loads due to transient events in a tokamak are analyzed and discussed. (authors)