The present disclosure is a bi-directional screwdriver, which includes a handle, a main shaft, a gearing which includes a driving gear, a driven gear, a transmission seat and an idle gear which is mounted on the idle gear axle on the transmission seat and is fitted between the driving gear and the driven gear for transferring motion. The handle rotates the driving gear. A grip ring is securely provided outside the idle gear axle. When the grip ring is gripped and the handle is rotated to rotate the driving gear, the driving gear rotates the driven gear in a reverse direction through the idle gear. The driving gear also has a first inside ratchet surface, and the driven gear also has a second inside ratchet surface. And the present invention also includes a reversing means which includes a reversing member, a first pawl member and a second pawl member, and a direction switch, in which the driving gear, the driven gear and the transmission seat are all sleeved on the reversing member, the reversing member is sleeved on the main shaft and able to rotate the main shaft.