In an electric actuator (100), a fast releasing mechanism (30) includes a rotary base (31), a coupling ring (32), a sleeve (34), and a clutch device (36). The coupling ring (32) rotates with the rotary base (31). Locking slots (322) are disposed on the coupling ring (32). The rotary base (31) can rotate with respect to the sleeve (34). Chain slots (343) communicating with the locking slots (322) are disposed on the sleeve (34). The clutch device (36) is correspondingly sleeved around the sleeve (34). Raised ribs (361) slidably connected to the locking slots (322) and the chain slots (343) are disposed on the clutch device (36). The sleeve (34) can be selected to move together with or move separately with the rotary base (31) by means of the axial movement of the clutch device (36).
