The utility model relates to a parallel type tripolar direct-current power transmission circuit. The parallel type tripolar direct-current power transmission circuit is used for connecting a transmitting-end alternating current power grid with a receiving-end alternating current power grid. The parallel type tripolar direct-current power transmission circuit includes a pole 1 circuit, a pole 2 circuit and a pole 3 circuit, an alternating current filter ACF1, an alternating current filter ACF2, a reactive power compensation device QC1 and a reactive power compensation device QC2; the input end of the pole 1 circuit is connected with a positive pole of the transmitting-end alternating current power grid; the output end of the pole 1 circuit is connected with a positive pole of the receiving-end alternating current power grid; the input end of the pole 2 circuit is connected with a negative pole of the transmitting-end alternating current power grid; the output end of the pole 2 circuit is connected with a negative pole of the receiving-end alternating current power grid; the input end of the pole 3 circuit is connected with a third pole of the transmitting-end alternating current power grid; and the output end of the pole 3 circuit is connected with a third pole of the receiving-end alternating current power grid. Compared with the prior art, the parallel type tripolar direct-current power transmission circuit of the utility model can assist in increasing transmission capacity of lines, fully utilizing towers of original lines and saving investment.