A torque wrench with functional lock includes a hollow main shaft, a tool member, an adjustable grip, a torque-adjustment elastic member, a clutch device, and a functional lock. The locking ring axially moves along the main shaft between a locked position and an unlocked position. When the locking ring is in the locked position, the rotation of the adjustable grip against the hollow main shaft is limited. When the locking ring is in the unlocked position, the rotation of the adjustable grip against the hollow main shaft is allowed, whereby the torque is adjusted. Therein, a percussion sound is produced when the locking ring is switched between the locked position and the unlocked position.