A plug connector includes a main body, a protecting assembly and an outer shell. The main body includes a connecting element for an electrical connection, a circuit board electrically connected with the connecting element, a soldering element fastened to a rear end of the circuit board, and an inner shell surrounding the circuit board. The protecting assembly is fastened to the main body. The protecting assembly includes a combination element surrounding the inner shell, and a protecting element fastened with the combination element. The outer shell surrounds the inner shell. The protecting element is fastened to a junction among the connecting element, the inner shell and the outer shell. The combination element has a first buckling assembly and a second buckling assembly. The first buckling assembly is buckled with the inner shell. The second buckling assembly is buckled with the outer shell.