The invention discloses a Halloween costume flame effect display device. The device comprises a base, a support rod, a horizontal shaft, a flame simulating portion, counter weight magnets, an illuminating lamp bead and a battery; two vertical sheets are mutually attached together to form the flame simulating portion to simulate flames, and light rays emitted by the illuminating lamp bead provide illumination for the flame simulating portion after being reflected by a stainless steel plate, so that the flame simulating portion is illuminated; the flame simulating portion can swing along with vibration of the base or under blowing of wind, and then swinging of the flames can be simulated. Compared with a flame simulating device in the prior art, the Halloween costume flame effect display device is truer and can better set off the festive atmosphere of the Halloween by contrast.