The invention discloses a combined water cup. The combined water cup comprises an inner cup, wherein the inner cup comprises a cup bottom and a cup wall; the cup wall surrounds the cup bottom to forma water holding cavity; a cup rim is integrally formed at the top end of the cup wall in an outward extending manner and comprises a horizontal section and a vertical section which are in smooth transition, the horizontal section, the vertical section and the outer side of the cup wall form a buckle; the inner cup is detachably provided with a cup sleeve surrounding the cup wall; a buckling part matched with the buckle is integrally formed at the top end of the cup sleeve; the buckle formed by the cup rim and the cup wall of the inner cup is matched with the buckling part at the top end of thecup sleeve, so that the cup sleeve can be stably connected with the inner cup and is also conveniently separated and detached from the inner cup; the water holding cavity holds hot drinks or ice-colddrink; the sheathed cup sleeve can protect a user; finally, the color and patterns of the inner cup are arranged to be different from those of the cup sleeve, so that the recognizability and transformation flexibility of the whole water cup are improved.