The invention discloses an electric wire angle folding device for watt-hour meter installing/wiring. The electric wire angle folding device comprises a plier body, wherein two chucks are arranged at the front end of the plier body; a cutter is arranged between the two chucks; a lower folding plate is arranged at the end part of one of the chucks; an upper folding plate is arranged at the end partof the other chuck; the lower folding plate comprises a lower transverse plate and a rear vertical plate; one end of the lower transverse plate is connected with one of the chucks; the other end of the lower transverse plate is perpendicularly connected with the end part of the rear vertical plate; a lower transverse groove is formed in the upper end face of the lower transverse plate; a length limiting device is arranged in the lower transverse groove; a rear vertical groove is formed in the front end face of the rear vertical plate; the upper folding plate comprises an upper transverse plateand a front vertical plate; one end of the upper transverse plate is connected with the other chuck; the end part of the upper transverse plate is perpendicularly connected with the front vertical plate; an upper transverse groove is formed in the lower end of the upper transverse plate; a front vertical groove is formed in the rear end face of the front vertical plate and communicates with the upper transverse groove; a length positioning device is arranged in the front vertical groove; the front vertical plate is matched with the rear vertical plate; and the front vertical groove and the rear vertical groove are corresponding in position.