The invention discloses a test device for the dielectric loss of a lacquered wire, which comprises an upper computer, a data collection device, a heating system, a circuit control system and an output device, wherein the upper computer respectively controls the circuit control system and the output device, the circuit control system controls the heating system to heat and test the lacquered wire,and the data collection device is connected with the heating system for collecting and transmitting test data to the upper computer for processing. The invention is suitable for testing the curing degree of the lacquered wire in a production process, directly represents the curing degree of the lacquered wire through the change of a curve of tan (delta), can adjust furnace temperature baking timeaccording to the change of the curve, and enables the curing degree of the lacquered wire to reach an optimal state and effectively control the product quality of the lacquered wire.