A wire stripper includes: a first main body having a main body portion, a rear grip, a lower engaging portion and an internal accommodating space; a second main body having an outer casing, an inner casing received in the outer casing, two upper engaging portions, two first rail holes located on both sides of the outer casing, two second rails, two first rails located on both sides of the inner casing and two second rail holes; and a third main body having a left casing and a right casing combined with each other, a front grip extending downwards from the left casing and the right casing, an acting portion connected between the second main body and the third main body, and a spring portion abutting in the front grip and the rear grip. The second main body and the third main body are received in the accommodating space.