Abstract: Disclosed is a trochoid pump for transferring high-viscosity liquids under high pressure. The trochoid pump includes an idler coupled to an inner through-hole inside a housing to be rotated, a rotor inserted into an inside of the idler, and a shaft configured to rotate the rotor, wherein the idler is provided with an inner toothed groove, into which the rotor is inserted and which has a plurality of projecting teeth, and recessed grooves, which are recessed with a predetermined depth along an outer circumferential surface thereof in a circumferential direction. Unlike an existing gear pump or trochoid pump, the trochoid pump for transferring high-viscosity liquids can reduce a viscous friction force, and can reduce the driving power.