Abstract: Frosting of gas intake filters in compressors at compressor stations along long-distance pipelines in winter may lead to significant increases in pressure losses. With consideration to available defrosting techniques, original defrosting process involving back-flushing system has been optimized to propose a modified logical algorithm for control over back-flushing system of gas intake filters. The optimized algorithm can acquire environmental temperature, humidity and wall temperature of gas intake filter to determine the dew-point temperature. By comparing with the acquired wall temperature of gas intake filter, the system diagnoses the possibility of frosting and then controls the back-flushing system to eliminate frost in gas intake filter. Research results show that the new control system effectively respond to possible frosting conditions in timely manner and dynamically control the back-flushing system. By maintaining environmental conditions in vicinity of gas intake filters at levels not subject to frosting, the new technique provides a feasible solution against frosting of gas intake filters in compressors.