The invention belongs to the field of railroad bogies and particularly relates to a narrow gauge bogie. To meet running requirements of narrow gauge railway lines, the narrow gauge bogie includes a front wheel set, a back wheel set, side frames, bolsters, brake devices, bottom center plates and side bearings. Wearing plates are arranged on the splayed surfaces of the bolsters and on vertical columns of the side frames, and the wearing plates located on the vertical columns of the side frames are fastened with the vertical columns of the side frames through folding head bolts. Clamping-in type sliding chute wearing plates are installed in sliding chutes of the side frames. The bolsters and the bottom center plates are of an integrated casting structure, and heat disk wearing plates are installed in the bottom center plates. Spring vibration dampers are composed of wedges, the wearing plates on the vertical columns of the side frames, bevel wearing plates and double damper springs. The wedges adopt combined wedges formed by wedge bodies and main friction plates. The side bearings adopt double-acting constant-contact elastic side bearings, and the brake devices adopt lower pull rods or middle pull rods structures. The narrow gauge bogie is simple in structure, easy to produce and convenient to overhaul, and can be applied to various wagons with various narrow gauges, the axle load smaller than or equal to 25t and the design speed as 100km/h.