The invention discloses a high-speed EMU power wheel pair axle box device for the conversion between a standard gauge and a wide gauge. The high-speed EMU power wheel pair axle box device comprises apower axle, wheels, a gear box and an axle box assembly, and is characterized in that a sliding mechanism is mounted on the power axle; the wheels and the axle box assembly are respectively fixed to the sliding mechanism in a sleeving manner; the sliding mechanism is used for driving the wheels to slide on the power axle when the gauge is changed, and transmitting the torque in coordination with the power axle during operation to drive the wheels to rotate; a locking mechanism is arranged between the sliding mechanism and the axle box assembly, and is used for locking and fixing the sliding mechanism before and after the gauge is changed; a bearing seat is mounted at the bottom of the axle box assembly and is used for carrying the vehicle when the sliding mechanism slides; and an axial positioning mechanism is arranged at two ends of the power axle and is used for achieving axial positioning of the axle. According to the high-speed EMU power wheel pair axle box device disclosed by theinvention, the sliding mechanism on the axle allows the wheels to slide laterally on the axle when the gauge is changed, so that the requirement for adapting to the changes in the gauge without stopping the vehicle to replace the bogie is met, the labour and material costs caused by the replacement of bogies during the multinational transportation are reduced and the operational efficiency is improved.