The present invention provides a direct current voltage divider and a capacitance and dielectric loss detection method thereof. The direct current voltage divider comprises an insulating bush, and a high voltage arm and a low voltage arm which are installed in the insulating bush. The top of the insulating bush is coaxially provided with a metal conductive barrel, the bottom end of the insulating bush is coaxially provided with a metal substrate, the high voltage end of the high voltage arm is electrically connected with the metal conductive barrel, and the metal substrate is grounded; the metal conductive barrel is electrically connected with a high-voltage polar line through a switch, and the lead connected with the low-voltage end of the high-voltage arm and the lead connected with the high-voltage end of the low-voltage arm are connected with each other through a short circuit jumper wire at the exterior of the insulating bush. The direct current voltage divider is good in heat radiation performance and good in reliability , can perform pressurization test of the high-voltage arm and the low-voltage arm, detect the capacitance and dielectric loss of the high-voltage arm and the low-voltage arm of the direct current voltage divider, and is simple in operation and high in safety.