A high voltage direct current soft-start circuit, comprising: a drive control unit , a first switch , a second switch , a load , and a first part of a connector , wherein a first end of the first switch is connected to a negative electrode (Vin-) of a high voltage direct current, a first end of the second switch is connected to the negative electrode (Vin-) of the high voltage direct current, and the drive control unit is connected separately to the first switch , the second switch , and the load , wherein the first part of the connector is connected to the drive control unit , and upon power-on, the first part of the connector is configured to communicate with a second part of the connector , to trigger the drive control unit to drive the first switch to turn on; and the drive control unit is configured to delay a preset time after driving the first switch to turn on, is configured to drive the second switch to turn on, and is configured to drive the load to start after the second switch is turned on, wherein the first part of the connector comprises one short pin and two long pins , wherein the short pin is connected to the drive control unit , one of the long pins is connected to a positive electrode pin of the second part of the connector , and the other long pin is connected to a first negative electrode pin of the second part of the connector ; and the short pin is configured to: after coming into contact with a second negative electrode pin of the second part of the connector upon power-on, cause the connector to generate a connection signal and send the connection signal to the drive control unit . a drive control unit , a first switch , a second switch , a load , and a first part of a connector , wherein a first end of the first switch is connected to a negative electrode (Vin-) of a high voltage direct current, a first end of the second switch is connected to the negative electrode (Vin-) of the high voltage direct current, and the drive control unit is connected separately to the first switch , the second switch , and the load , wherein the first part of the connector is connected to the drive control unit , and upon power-on, the first part of the connector is configured to communicate with a second part of the connector , to trigger the drive control unit to drive the first switch to turn on; and the drive control unit is configured to delay a preset time after driving the first switch to turn on, is configured to drive the second switch to turn on, and is configured to drive the load to start after the second switch is turned on, wherein the first part of the connector comprises one short pin and two long pins , wherein the short pin is connected to the drive control unit , one of the long pins is connected to a positive electrode pin of the second part of the connector , and the other long pin is connected to a first negative electrode pin of the second part of the connector ; and the short pin is configured to: after coming into contact with a second negative electrode pin of the second part of the connector upon power-on, cause the connector to generate a connection signal and send the connection signal to the drive control unit . <EOS>