The invention discloses a cable direct current resistance measuring device and an application method thereof. The cable direct current resistance measuring device is capable of accurately measuring the resistance of cable conductors with different sectional area and ensuring good contact of potential joints. The cable direct current resistance measuring device includes a base, two current pressurewelding modules and two potential pressure cutting modules; the current pressure welding modules are arranged at the two ends of the measuring device and are slidably connected with the base, and each current pressure welding module includes a current interface and a conduction joint; the potential pressure cutting modules are arranged between the current pressure welding modules, each potentialpressure cutting module includes an upper potential pressure cutting module body and a lower potential pressure cutting module body, each upper potential pressure cutting module includes an upper potential pressure cutting module potential interface, each lower potential pressure cutting module includes a lower potential pressure cutting module potential interface, the upper potential pressure cutting module bodies can move relative to the lower potential pressure cutting module bodies, the upper potential pressure cutting module bodies and the lower potential pressure cutting module bodies are connected with blades respectively, and the blades are electrically connected with the upper potential pressure cutting module potential interfaces and the lower potential pressure cutting module potential interfaces respectively.