Abstract: An outlet structure for an encoder includes: an encoder case, a metal ring, a fixing member, and two O-shaped rings. A first cable through-hole is disposed in the encoder case. The metal ring is disposed in the first cable through-hole to clasp a shielding layer of a cable. The fixing member includes a second cable through-hole, and the fixing member fits with interference into the first cable through-hole from an outer side of the encoder case. The first O-shaped ring fits onto the fixing member to seal a slit between the fixing member and the encoder case. The second O-shaped ring in the second cable through hole seals a slit between the fixing member and the cable, and the second O-shaped ring applies an elastic force to the metal ring such that the metal ring remains abutting against the encoder case.