The invention relates to the technical field of power transmission and transformation, and particularly relates to a single and three-phase DC loop resistance tester calibrating device. A first standard device is connected with a second standard device and a third standard device by star-shaped band neutral points, i.e. the C2 contact of the first standard device is connected with the C2 contact of the second standard device and the C2 contact of the third standard device. The C1 contact lead-out wire of the first standard device is A, and the P1 contact lead-out wire is a. The C1 contact lead-out wire of the second standard device is B, and the P1 contact lead-out wire is b. The C1 contact lead-out wire of the third standard device is C, and the P1 contact lead-out wire is c. The neutral point lead-out wires are O and o. Advantages of the single and three-phase DC loop resistance tester calibrating device are that 1, multipoint detection of a three-phase DC resistance tester, a single-phase DC resistance tester and a loop tester is completed by one time of wiring, including main indicators like a current value, a resistance value, resolution and current overshoot; 2, resistance is live continuously adjustable; and 3, resistance range is wide and stability is high.