The invention belongs to a thermostat testing device; and in order to solve the problems in the prior art that a dial gauge and a thermometer are easily loosened during the test caused by insecure fixation, and a stirring magneton is easily adsorbed to the thermostat spool when the rotating speed is adjusted, resulting in a long time consumed by the temperature rise test of the thermostat and an adverse affect on the test results, the invention provides a thermostat temperature rise testing device. The thermostat temperature rise testing device comprises a temperature measuring tank, a fixingframe, a support frame, a hollow self-locking bolt and a plurality of hanging rods; the fixing frame is placed in the temperature measuring tank and has a clearance fit with the temperature measuringtank; the self-locking bolt is fixed to the center of the fixing frame the screw; the hollow part of the self-locking bolt is used for fixing the dial gauge; the thermometer passes through the fixingframe; and the support frame is placed on the top of the temperature measuring tank, and the support frame and the fixing frame are connected to a whole by the hanging rods. During the test, through adjusting the hanging rods, the support frame and the fixing frame which are connected to a whole, the contact distance and angle of the dial gauge head to the center of the thermostat spool can be quickly adjusted, and the test of thermostat spools of different heights can also be performed.