The invention discloses a temperature control circuit in a direct current transformer for an electric automobile. The temperature control circuit in the direct current transformer for the electric automobile comprises an operational amplifier, an in-phase input end of the operational amplifier is connected to the ground, a divider resistance R3 and a divider resistance R4 are connected between an inverted input end of the operational amplifier and a reference voltage after being connected in series, the inverted input end and the output end of the operational amplifier are further connected with a feedback branch, an output end of the operational amplifier is connected with a current control end of a PWN control chip, one end of a divider resistance R5 is connected between the divider resistance R3 and the divider resistance R4, the other end of the divider resistance R5 is connected with an output current sampling contact of the direct current transformer, the divider resistance R6 is connected with the divider resistance R5 in parallel after being connected with a temperature inductive switch in series, and the temperature inductive switch is arranged on an outer shell of the direct current transformer. The temperature control circuit in the direct current transformer for the electric automobile has the advantages that when the temperature of the outer shell of the direct current transformer is higher than a set temperature value, the output current of the direct current transformer is reduced by a half, so that the working temperature is controlled effectively, and potential safety hazards are completely eradicated.