The invention relates to a water-injection foot massager, in particular to a flat rotary water-injection foot massager for massaging feet. An eccentric block, which is coaxial with a rotating shaft and rotates with the rotating shaft, is arranged between the rotating shaft and a vibrating disk, the eccentric block is integrated with the vibrating disk through a bearing, and the vibrating disk is mounted on a foot washer container through a plurality of flexible shafts. Compared with the prior art, the vibrating disk of the invention is mounted on the foot washer container through a plurality of flexible shafts, and synchronously the flexible shafts are used for absorbing shock so that the vibrating disk is separated from the base of a vibrating device; when the vibrating disk runs, the foot washer does not vibrate with the vibrating disk so as to greatly increase the service life of the foot washer; the foot massager is arranged at a power transport unit and provided with a sealing device for water seal so as to increase application safety factor; and synchronously, the control switch key is a touch key, which is not easily worn and aged and does not generate noise while using a mechanical key.