The invention provides a grape trellis with the rainproof function, and belongs to the technical field of grape planting. The grape trellis comprises bearing frames, transverse beams, longitudinal beams, a guiding rail, a sliding support, a driving motor, a gear, a rack, a plastic film and a rainfall metering assembly. The transverse beams and the longitudinal beams are arranged at the upper ends of the bearing frames in a staggered mode, the longitudinal beams are arc, the middles of the longitudinal beams are high, and the two ends of the longitudinal beams are low; the rack is fixed on the transverse beam on the outermost side; the sliding support is arranged on the guiding rail in a sliding mode, the driving motor is coaxially connected with the gear, the gear is engaged with the rack, pulley grooves are formed in the inner sides of the two transverse beams on the outermost side, pulleys are arranged on the pulley grooves in a sliding mode, the two ends of the plastic film are connected with the pulleys through ropes at equal intervals, a floating ball of the rainfall metering assembly can float up and down and is arranged on a guiding rod, and a trigger switch is arranged at the upper end of the guiding rod and connected with the driving motor. By means of the grape trellis with the rainproof function, it is achieved that the grape trellis is automatically covered and opened through the plastic film, and growing of grapes is facilitated.