In view of the problems of nonuniformity of forward error correction coding(FEC) technical standards for 100G optical transmission network(OTN) equipment and difficulties in interconnection of line side interfaces, this paper first introduces the principle and defects of 100G interconnection technology for single manufacturer's equipment, and then proposes a device technology compatible with line side coherent interfaces of several manufacturers' 100G OTN equipment. The module of analog / digital, digital / analog and data pre-processing is introduced between the analog coherent optical(ACO) functional unit and the digital signal processing(DSP) chip to complete the high-speed analog / digital, digital / analog conversion function. Through the data pre-processing function, the manufacturer's category information of the signal is analyzed and the back-end DSP chip is selected and switched. The experimental results show that the equipment scheme can be compatible with 100G OTN equipment of several manufacturers.