The invention relates to a Co bogie for a heavy-load alternating-current transmission power freight locomotive on a railway, in particular to a Co bogie for a high-adherence heavy-load freight locomotive, comprising wheel pair driving systems, a framework, a two-series suspension device, a traction device, a motor suspension device and a braking device. Three wheel pair driving systems are installed on each bogie and adopt integrated axial suspension drives with elastic coupling couplers and alternating-current traction motors; gear boxes are in load bearing structures; a first-axle wheel pair axle box device and a third-axle wheel pair axle box device are provided with integrated conical bearings with small axial clearances, and a second-axle wheel pair axle box device is provided with an integrated cylindrical bearing with a large axial clearance. The bogie structure provided in the invention can satisfy the adoption requirements of 25-ton axle-load electric locomotives.