Abstract: As a core technical equipment for heavy-load transportation, the fault identification and maintenance technology of commercial vehicle power transmission systems directly affects operational efficiency and safety performance. Faults in the power transmission system present diverse characteristics such as mechanical wear, hydraulic failure, and abnormal electrical control. Traditional empirical judgment methods are difficult to meet the actual needs of rapid and accurate location of complex faults. By establishing a multi-dimensional technical system including fault feature identification of mechanical transmission chains, abnormal detection of hydraulic and electronic control integrated systems, and diagnosis and separation of compound fault modes, and combining systematic maintenance methods such as optimized design of maintenance processes, precision processing and repair technology, and assembly quality control standards, a complete technical solution for fault identification and maintenance has been formed. Through practical application verification in large commercial vehicle maintenance service enterprises, this technical system has achieved significant improvements in terms of fault identification accuracy, diagnostic efficiency, and maintenance quality.