Grounding detection circuit and method and three-phase alternating current charging pile

The invention discloses a grounding detection circuit and method and a three-phase alternating current charging pile, and the circuit comprises a three-phase alternating current input end which provides a high-voltage alternating current for the three-phase alternating current charging pile according to an external alternating current; the input end of the rectifying unit is connected with the three-phase alternating current input end, and the rectifying unit is used for rectifying the high-voltage alternating current into direct current and outputting the direct current; the input end of the detection circuit is connected with the output end of the rectifying unit, and the detection circuit judges the grounding condition of the three-phase alternating current charging pile according to the output direct current and outputs a detection signal through the output end. Real-time grounding detection is carried out on the three-phase alternating current charging pile through the detection circuit, meanwhile, the t