Oil temperature measurement device of triaxial high-voltage tester

Disclosed is an oil temperature measurement device of a triaxial high-voltage tester. A cylindrical freezing cavity is vertically fixed at a middle part of a slabby subbase. A hydraulic oil cavity and a cold fluid chamber sleeve externally the freezing cavity. The freezing cavity is filled with a rock-soil body. The upper and lower parts of the rock-soil body are an upper nylon plate and a lower nylon plate, which are in precision cooperation with the freezing cavity. Thermocouple measurement points are attached at the outer part of the freezing cavity and connected to a thermocouple outside the subbase. A hydraulic oil input pipe, a cold liquid input pipe, a cold liquid output pipe, and a hydraulic oil output pipe are installed respectively at the lower parts and upper parts of the hydraulic oil cavity and the cold liquid cavity. A switch valve is arranged on each of the pipes. The top part of the freezing cavity is provided with a pressure cap in embedment fit with the freezing cavity. The device is capable of achieving a soil-body-freezing effect through an external circulation cold liquid and measuring the temperature of the hydraulic oil which applies a confining pressure to the soil body through the thermocouple attached outside the soil body so that temperature change of the hydraulic oil in the whole freezing process can be displayed directly through the thermocouple.