The invention discloses an easy-to-clean water cup, comprising an outer cylinder, a liner, an upper cover, a plug and a lower cover, wherein an inner edge extending inwards is arranged at an opening of the upper part of the outer cylinder, the inside edge of the inner edge extends downwards so that the cross section of the inner edge is in 7 shape; the plug comprises a round base plate located atthe lower part and a conical convex part integrally formed with the base plate and extending upwards, a first cushion layer and a second cushion layer are sequentially arranged outside the convex partfrom inside to outside, and the first cushion layer, the second cushion layer, the base plate and the convex part are all made from rubber material; the liner is located in the outer cylinder, the upper end of the liner props against the lower part of the inner edge, and a rubber sealing ring is arranged between the upper end of the liner and the inner edge; the plug is adapted to an opening at the lower part of the liner; the upper cover is screwed to the upper part of the outer cylinder; the lower cover is screwed to the lower part of the outer cylinder; and the lower surface of the base plate is supported on the lower cover. The easy-to-clean water cup has the advantages of being easy to clean and relatively long in service life.