The invention provides a cup getting device of a water dispenser, wherein, the cup getting device comprises a rocker arm, a sliding block and guide sliding rails. The slide block is provided with a first flange and a second flange. The cup getting device is characterized in that the sliding block is connected with the guide sliding rails in a sliding manner, the rocker arm and the sliding block are matched and connected, the rocker arm drives the sliding block to do slip motion between the guide sliding rails, the first flange is positioned in a clearance between rolled edges of two stacked cups, the second flange is positioned below a bottommost cup edge, and the slip motion of the sliding block drives the first flange and the second flange to respectively do rectilinear motion along with the clearance and the bottommost cup edge. According to the embodiments of the invention, the cup getting device can improve the accuracy of getting cups and can easily get the cups at the same time.