Abstract: Basic work principle of gas-power generator (Caterpillar G3412) is introduced and scuffing phenomenon of the generator produced in Sebei Initial Compressor Station of Sebei-Xining-Lanzhou Gas Transmission Pipeline is analyzed. Based on analysis result, the generator's accessories including cylinder case, plunger, compressed rings and nil-control rings, high-voltage coil, sparking plug and water-temperature sensor are replaced. Daily care method for the generator unit is presented.