The present invention discloses a bottle washing machine mechanical arm with an antifouling device. The bottle washing machine mechanical arm comprises a mechanical arm, a slide bearing, a water eliminator and a bearing support. The bearing support is fixed at the inner side of the water eliminator. The slide bearing is arranged in the bearing support. The mechanical arm is mounted in the slide bearing. The outer side of the water eliminator is provided with an antifouling sleeve which is sleeved at the mechanical arm. The bottle washing machine mechanical arm with the antifouling device had the advantages of simple and reasonable structure, being capable of effectively preventing the pollution of the water used for cleaning and keeping the clean and bright appearance.