A quick-assembly front wheel device of a bicycle is pivotally disposed on a single-bladed fork and includes a wheel and a brake disc. The single-bladed fork has a pivotal end, the pivotal end has a first surface and a second surface, a shaft hole is opened passing through the first surface and the second surface, the wheel is located on the first surface and has a first axle shaft passing through the shaft hole, and the brake disc is located on the second surface and has a second axle shaft to pass through the shaft hole. The first axle shaft and the second axle shaft can be butted together. Therefore, the front wheel is capable of being quickly disassembled and mounted.