Abstract: A bi-directional ratchet wrench includes a handle with a head at a front side formed a housing trough to hinge a ratchet wheel which has ratchet teeth on the perimeter and a knob strut jutting from one end surface, a switch element located in a swivel space formed at the housing trough with a plurality of harness teeth formed respectively on the left and right sides of a front end to allow the harness teeth on one side to engage with the ratchet teeth, and having a rear side formed with two concave portions, and confined at a selected swivel angle on the left and right sides by two retaining troughs formed in the swivel space, a butting unit having an elastic element embedded in the head and a spherical butting member butting the concave portions, and a sealing lid to seal the ratchet wheel and switch element.