The utility model belongs to the technical field of material performance test is experimental, accurately say, involve a fine motion fatigue test device of height temperature high -pressure circulating water. The device mainly by high temperature high -pressure circulating water system, autoclave, tired machine, normal direction normal pressure apply the system, five parts of control system are constituteed. The water chemistry accurate controllable high temperature high -pressure circulating water environment of high temperature high -pressure circulating water system for providing the laboratory in the autoclave and needing, alternating load is applyed to the fatigue testing specimen in the autoclave to tired machine, the normal direction normal pressure apply the system in to the autoclave fatigue testing specimen gauge length segment table face apply controllable normal pressure, control system control high temperature high -pressure circulating water system and tired machine. At the fatigue test in -process, fatigue testing specimen gauge length section repeated deformation, the wearing and tearing pressure head keeps static, and the normal position fine motion fatigue test inthe high temperature high -pressure circulating water environment is realized to wearing and tearing pressure head and fatigue testing specimen gauge length section the contact region repeated scraping.