The invention discloses a whole-body 360-degree full-coverage detection system for a motor train unit. The system comprises a bottom portion detection device and a middle-upper portion detection device; the bottom portion detection device comprises a fan abnormal sound detection unit (2) and a contact type scratch detector (8); a deep flaw detection unit (3) is arranged at one end of the fan abnormal sound detection unit (2); a wheel set appearance detection unit (4) is arranged at one end of the deep flaw detection unit (3); and the middle-upper portion detection device comprises a vehicle window image monitoring unit (1), a pantograph abrasion and pressure detection unit (9) and a vehicle roof equipment dynamic detection unit (10). The invention further discloses a corresponding method.With the detection system adopted, different detection modes are adopted for different components and positions of the motor train unit; after the motor train unit passes through a detection shed, thedetection results of various components of the vehicle can be obtained; the fault information of the motor train unit can be quickly and efficiently obtained; detection efficiency is high; and the workload of manual detection operation is reduced.