Objective To analyze the common fault causes and maintenance methods of the oxygen concentration monitoring module of Drager Savina 300 ventilator by studying typical cases to ensure the stable operation of medical equipment. Methods The process of case sharing involved ameticulous examination of each of the three cases, starting from the identification of fault phenomenon, followed by a systemic analysis of underlying fault causes, culminating in a step-by-step resolution according to established fault handling procedures. During maintenance, the maintenance mode detection was used to quickly locate problems; the step-by-step elimination method was adopted to narrow fault range; when deemed necessary, parts were replaced to ensure the restoration of equipment functionality. Results Oxygen concentration module faults were mostly related to air circuit tightness, oxygen valve components, and sensors. Checking and eliminating them one by one according to the air circuit diagram successfully solved different fault problems. All three cases were effectively repaired by this method, restoring the normal oxygen concentration monitoring function of the ventilator. Conclusion Ventilator maintenance requires accumulation and sharing of practical experience. Maintenance personnel should master various skills related to circuits and air circuits, and be proficient and specialized to ensure the reliable operation of medical equipment and provide strong guarantee for patient safety.