Provided is a direct current negative dimming circuit, comprising a first electrical switch, a second electrical switch and first to third resistors, a control end of the first electrical switch is connected to a dimming signal output end of a main chip to receive the first dimming signal, and a first end of the first electrical switch is connected to a voltage end to receive a first high voltage level signal, and a second end is connected to a control end of the second electrical switch, and a first end of the second electrical switch is connected to a dimming signal receiving end of a backlight module to output the second dimming signal, and a second end receives a second high voltage level signal, and a voltage level of the first dimming signal is opposite to a voltage level of the second dimming signal.