The gas valve is the most vulnerable component of a reciprocating natural gas compressor, and its state is closely related to the operating state of the compressor. However, valve faults cannot be clearly diagnosed through the frequency domain. To address this difficulty, this paper analyzes the valve vibration signals from the perspective of time-domain mechanisms. The main research work includes analyzing various vibration sources of the gas valve through on-site vibration data and key phase signals, and analyzing fault signals based on the impact of vibration sources. The analysis of on-site fault vibration signals has well confirmed the accuracy of vibration source classification and the reliability of time-domain analysis methods. The results show that fault diagnosis of compressor valves through time-domain signals is a reliable approach.