The utility model relates to an in-situ cooling device for an inner hole rotary plasma spraying base body. The device comprises a liquid guide module, a heat dissipation module and a liquid storage module; the liquid guide module comprises a fixed clamping groove, a lower liquid guide pipe, liquid outlet pipes and a liquid guide box, the liquid guide box is of a cylinder structure with the cylinder wall being of a hollow structure, and the lower portions of the two sides of the liquid guide box are each provided with one liquid outlet pipe; the fixing clamping groove is formed in the inner edge of the top end of the liquid guide box, and a circle of lower liquid guide pipes are evenly distributed around the fixing clamping groove. The heat dissipation module comprises two identical semicircular heat dissipation cambered surface bodies, lower liquid inlet holes are formed in the lower surfaces of the heat dissipation cambered surface bodies, and upper liquid inlet holes are formed in the upper surfaces of the heat dissipation cambered surface bodies. The in-situ cooling device is simple in structure, low in cost, convenient to operate and capable of being used for achieving in-situcooling of the inner hole rotating plasma spraying base body.