A children's tricycle comprises a body, a front wheel pivotally assembled to the body, a first pedaling assembly assembled to the front wheel, a second pedaling assembly assembled to the front wheel, a screw for making the first pedaling assembly threaded with the second pedaling assembly. A first inserting rod of the first pedaling assembly and a second inserting rod of the second pedaling assembly are connected to the front wheel separately, such that the first and second pedaling assemblies can be assembled to or detached from the front wheel quickly. The first and second pedaling assemblies can be assembled to the tricycle for the child to step on, and can also be detached from the tricycle when the child is learning to walk, such a tricycle is not only money-saving since the parents don't need to buy a special baby walker additionally, but also has high convenience and security.