The invention discloses an automatic vehicle-mounted mobile power charging and exchanging station for an electric vehicle and a method for quickly exchanging a battery. The automatic vehicle-mounted mobile power charging and exchanging station comprises a tractor, a semitrailer and a battery box storage rack, a battery box, an automatic power exchanging device, a charging system, an electric quantity counting system, an automatic control unit and the like which are arranged on the semitrailer, wherein the storage rack can store a plurality of battery boxes three-dimensionally; the battery boxes are standard exchanging modules connected with a battery house on the lower part of a vehicle body by using a plurality of quick-opening locking bolts; the automatic power exchanging device comprises a lifting table, a transmigration machine, a shifting machine and a plurality of unlocking / locking bushings; the automatic power exchanging device can automatically transport and store the battery boxes, and lock or unlock the battery boxes and the battery house due to mutual matching of the lifting table, the unlocking / locking bushings and the quick-opening locking bolts, so automatic dismantling and exchange of the battery boxes can be realized; and the charging system is used for automatically charging the battery boxes. The station is complete in system, compact in structure, flexible in maneuvering, low in investment and short in construction period, so the automatic power charging / exchanging requirement of the battery of the electric vehicle can be met.