An optical fiber direct amplifying station which has same/different frequency transmission function comprises a near-end machine and a far-end machine which are connected with optical fiber. In the near-end machine, three ends of the circulator are respectively connected with a first frequency receiving/transmitting channel of the duplexer, a radio frequency output end of the optical fiber and a first input end of the multiplexer. A second input end of the multiplexer is connected with a second frequency transmitting channel of the duplexer, and the output end is connected with a radio frequency input end of the optical module. In the far-end machine, the input end of the shunt is connected with the radio frequency receiving end of the optical module, and a first frequency output end of the shunt is connected with the input end of a first main power amplifier. A second main power amplifier is connected between a second frequency output end of the shunt and a second frequency receivingchannel of the duplexer. The output end of the low-noise amplifier is connected to the radio frequency transmission end of the optical module. The three ends of a first radio frequency switch of which the switching is controller by a controller are respectively connected with the first frequency receiving/transmitting channel of the duplexer, the input end of the low-noise amplifier and the output end of the first main power amplifier.