The invention relates to a heart assisting device, in particular to a magnetic fluid suspension type axial pump heart assisting device implanted into the human body in the field of biomedical engineering. The magnetic fluid suspension type axial pump heart assisting device is characterized in that a section of flow channel is divided into an inner flow channel and an outer flow channel by an outer ring wrapping the middle section of an impeller blade, and spiral tooth ripples are engraved on the outer wall of the ring; the top wall of the tooth ripples is in an oblique shape, so that an inflowing opening of the outer flow channel is large, and an outflowing opening is small, and an impeller is subjected to hydraulic pressure when rotating to be radially suspended; an opening is formed in the side wall of the tooth ripples; a pair of convex-concave magnetic cones are embedded in the back end of an impeller hub and a back guide blade hub, and are in the axial magnetic direction, and unlike poles attract each other; a backward pull force generated on the impeller resists the blood forward push force borne by rotating the impeller, and a stator iron core has a binding force, so that the impeller is axially suspended, and thus the impeller is fully suspended; the impeller and front and back guide blade hubs are respectively embedded with two pairs of sliding bearings, which protect the magnetic cones, blades, and the inner wall of a pump pipe, and position and help the impeller suspension.