The present invention relates to a single-hole puncher with ease of alignment comprising a base and a punching unit; the punching unit is disposed on the base; a hole is disposed on the base in a position corresponding to the punching unit; a L-shaped right-angle receptacle with two vertical flanges is disposed between the base and the punching unit; the punching unit and the right-angle receptacle are vertically disposed facing each other. Since the L-shaped right-angle receptacle of the present single-hole puncher allows convenient and efficient paper alignment, the present invention, in comparison with available single-hole punchers, has the advantages of being simple in construction, easy to operate, convenient to be carried around and of high punching efficiency and precision. It can also punch binding holes of various distances in between. The structure of the L-shaped right-angle receptacle can be widely applied to various types of single-hole punchers and even two-hole (multiple-hole) punchers.