Abstract: Objective: The repair schedule of vehicles is an important basis for determining the design scale of vehicle bases. There is no uniform national standard yet for the repair schedule of city rail express (abbreviated as CRE) vehicles. In order to accurately calculate the design scale of CRE vehicle bases, it is necessary to conduct research on the repair schedule of CRE vehicles. Method: Based on the design practice of Chengdu Metro Line 18, the characteristics of AC (alternating current) 25 kV CRE vehicles are analyzed. Statistical comparison of vehicle maintenance and repair process of CRE lines that are already in operation (such as Beijing Capital Airport Line and Wenzhou Urban S1 Line).is conducted, characteristics of the mileage, repair cycle, and downtime of CRE vehicles are analyzed. Based on the analysis of the main factors affecting the repair process CRE vehicles (vehicle technical parameters, the maximum operating speed, and line conditions), the repair mileage and repair cycle for major repair, regular repair, and weekly/monthly inspections of AC 25 kV CRE A\|type vehicles are proposed. Result &Conclusion: The proposed maintenance cycle, maintenance time for double day inspection are 2 days and 2 hours; the maintenance mileage and downtime for biweekly inspection are 11 250 vehicle kilometers and 0.5 days; the following sequences are 67 500 vehicle kilometers and 2.0 days for maintenance mileage and downtime in three months; 150 000~20 000 vehicle kilometers and 7.0 days for regular inspection; 750 000 vehicle kilometers and 5\|year maintenance cycle for unwheeling repair; 1.5 million vehicle kilometers and 10\|year maintenance cycle for major repair.