Hydrothermal reaction device as well as method and system of treating powder material thereby

The invention provides a hydrothermal reaction device as well as a method and a system of treating a powder material thereby. The device comprises a tubular reactor body, a first heating portion and a second heating portion; the first heating portion is controlled by an external control device to heat the first end portion of the tubular reactor body at a reaction temperature corresponding to to-be-reacted slurry; the second heating portion controlled by the control device heats the second end portion of the tubular reactor body at a reaction temperature, and after the to-be-reacted slurry reaches the reaction temperature, the second end port of the tubular reactor body is heated at a first set temperature and a second set temperature according to a set mutant period; and the tubular reactor body conducts heat generated by the heating portions to the inside to-be-reacted slurry thereof so as to enable convective mixing and reacting of the to-be-reacted slurry, wherein the first set temperature is greater than the reaction temperature and the second set temperature is smaller than the reaction temperature. When the hydrothermal reaction device provided by the invention treats the powder material, the heating time can be shortened.