The utility model belongs to cups, particularly a new side push button lid. The cup lid comprises a threaded body, a hold-down piece, a sealing seat, an upper lid body, an upper lid plate, a push rod, a sealing valve, and a button connected successively from bottom up. The middle area of the lower end of the push rod is movably connected with the holder on the hold-down piece; one end of the push rod is connected with a sealing valve in a snap-fit manner; the other end is connected with a drive rod of the button; and the upper end of the seal valve abuts the water outlet of the upper lid plate. The pressed button drives the drive rod to apply a pushing force to the push rod to force the sealing valve to move downward, the sealing valve is removed from the water outlet and water is supplied.