Abstract: Condition-based maintenance is a kind of maintenance strategy that can determine equipment maintenance by fault diagnosis expert system based on the results of real-time state-monitor and periodic detection. The present situation of compressor sets vibration monitoring technology is introduced. And functions of different online monitoring systems of PetroChina's longdistance gas pipeline compressor sets are analyzed. Then, the development strategy of condition-based maintenance of compressor sets is proposed. Using condition-based maintenance technology of aero-engine for reference, special research on different equipments can be carried out to evaluate the technical state of compressor sets accurately. And unified remote monitoring and fault diagnosis center for compressor sets can be established to provide reliable evidence to condition-based maintenance.