The invention discloses a power distribution network line current acquisition device and method. The power distribution network line current acquisition device comprises an arc-shaped iron core current transformer, a microprocessor, a data communication module and a power source module; the arc-shaped iron core current transformer is connected with the microprocessor through an integral circuit; the data communication module is connected with the microprocessor; the integral circuit, the microprocessor and the data communication module are all connected with the power source module; the arc-shaped iron core current transformer comprises an arc-shaped iron core, a secondary coil, the integral circuit, a bracket and a porcelain insulator; the two secondary coil comprises a measuring winding and a power source winding; the measuring winding and the power source winding are wound on the arc-shaped iron core; two ends of the measuring winding are connected with the integral circuit; and two ends of the power source winding are connected with the integral circuit. With the power distribution network line current acquisition device and method of the invention adopted, problems in current measurement on branch lines of a power distribution network line can be solved. According to the power distribution network line current acquisition device and method, an external power source is not required. When the power distribution network line current acquisition device is installed, the conductors of the power distribution network line are not required to be cut off.