The utility model provides a power source structure for a DC power transmission line on-line monitoring device, so that solar cell panels and charging cells can be directly installed on overhead conductors of a DC power transmission line, and the problem of power supplying of the conductor measurement mode of the DC power transmission line on-line monitoring device is solved. In the power source structure, spacer rods on the overhead conductors serve as a main body framework; the solar cell panels are connected with the spacer rod through a hinge and are angle-adjustable; the bottom ends of the solar cell panels are fixedly arranged on the spacer rod through support frames; and lead wires of the solar cell panels are voltage output ends of solar cells, and are connected with a cell box through aviation plugs. Compared with the prior art, by utilizing the power source structure provided in the utility model, the DC power transmission line on-line monitoring device can be arranged on the conductors, and running information of the conductors of the power transmission line can be directly measured, thereby filling the blank of conductor installation mode of the DC power transmission line on-line monitoring device.