The invention discloses a heat radiation device for a low-voltage control box of a new energy vehicle. The heat radiation device includes a box body, wherein the inner wall of the box body is providedwith a sleeve rod; the inner wall of the sleeve rod is provided with a bottom block; a top block is arranged at the right side of the bottom block; the inner wall of the top block is provided with apush rod; the outer wall of the push rod is provided with a latch; the outer wall of the latch is provided with a base; the inner wall of the base is provided with a top seat; the outer wall of the right side of the top seat is provided with a fixed block; the outer wall of the left side of the fixed block is connected with the outer wall of the right side of the top seat; the outer wall of the right side of the fixed block is provided with a motor; the inner wall of the motor is provided with a rotating shaft; the outer wall of the rotating shaft is connected to the inner wall of the motor; the outer wall of the rotating shaft is provided with a fan blade; and the inner wall of the fan blade is connected with the outer wall of the rotating shaft. For the heat radiation device for a low-voltage control box of a new energy vehicle, through coordination among the sleeve rod, the push rod and the latch, under the effect of the base and the top seat, the sleeve rod fixes the push rod in the sleeve rod, so that the push rod can slide inside the sleeve rod so as to adjust the inclination angle of the base, so that the heat radiation device for a low-voltage control box of a new energy vehicle is suitable for promotion and application.