A positioning apparatus includes a mounting plate, a driving assembly, and two first position assemblies. The mounting plate defines a first guiding groove. The driving assembly is mounted on the mounting plate and includes a driver, and a transfer rod coupled to the driver. The first pivoting assembly includes a first coupling rod and a second coupling rod. The first coupling rod is movably received in the first guiding groove and pivotably coupled to the transfer rod. The second coupling rod is movably received in the first guiding groove and pivotably coupled to the transfer rod. The first position assemblies are respectively pivotably coupled to the first coupling rod and the second coupling rod.