The invention discloses a combined generating device of a power transmission tower. The combined generating device solves the problems that an existing generating device is low in generating efficiency and high in power. The combined generating device comprises a power source, a switch, a stepping motor, a solar cell panel, a ULN2003 stepping motor drive chip, an MSP430 single-chip microcomputer, a light inductor and a wind power generating device, wherein the solar cell panel is connected with an output shaft of the stepping motor. The output end of the solar cell panel is connected with the negative electrode of the power source, the positive electrode of the power source is respectively connected with the input end of the MSP430 single-chip microcomputer and one contact of a relay, the power source is connected with the light inductor and the wind power generating device, the output end of the MSP430 single-chip microcomputer is respectively connected with the input end of the stepping motor drive chip and a coil of the relay, the other contact of the relay is connected with the input end of the stepping motor drive chip, and the output end of the stepping motor drive chip is connected with the stepping motor. According to the combined generating device, generating efficiency of solar energy is improved, and sufficient electric energy is provided for a power utilizing device of the power transmission tower.