The present disclosure discloses a wheel assembly structure and a child activity center. The wheel assembly structure includes a connection base and a wheel assembly that is deployable. The wheel assembly is pivotally connected to the connection base. The wheel assembly has a deployment state and a storage state. An adjustment mechanism is provided between the connection base and the wheel assembly. The adjustment mechanism is configured to switch the wheel assembly into the storage state from the deployment state. When the wheel assembly is in the deployment state, the wheel assembly is deployed to a first position to move the connection base. When the wheel assembly is in the storage state, the wheel assembly is stored to a second position to stably place the connection base. The wheel assembly structure has a simple overall structure, which facilitates production and lowers production costs.