The invention relates to a portable water-borne pedal boat. The pedal boat comprises a foldable frame, a pushing device and buoyancy devices, wherein the buoyancy devices are detachably connected to the foldable frame. The foldable frame comprises pedals and a chain wheel assembly, wherein one end of the chair wheel assembly is connected with the pedals, and the other end of the chair wheel assembly is in matched connection with the pushing device. The chair wheel assembly drives the pushing device to move to realize forwarding or retreating of the pedal boat. On the basis of an original foldable bicycle, front and back wheels of the portable water-borne pedal boat are detached, then a guiding device, the pushing device, the front buoyancy device and the rear buoyancy devices are adopted for replacing original front and back wheels, and therefore portable water-borne pedal boat is simple and light in structure and low in cost. The foldable structure and the detachable structure realizecarrying and storing conveniently; the buoyancy devices are installed in the front-and-back direction, and therefore the safety and entertainment are high as a whole; the portable water-borne pedal boat can be used as public entertainment equipment of a casino or a water ports instrument of personal entertainment and exercise.