The invention discloses an instant heart motion measuring method for human body elbow joint anteflexion and rear protraction around instant heart motion, and belongs to the technical field of measurement. The method comprises the following three steps of collecting human body upper limb motion data, wherein two mark point motion blocks are fixed to an operator upper arm and forearm flanges, and when the forearm performs slow flexion and extension motion, human body upper arm and forearm motion information is obtained through a VICON measuring system; building a forearm motion model, wherein the human body upper arm and forearm are adopted as a rigid body, and a kinematic model of the forearm around the instant heart motion relative to the upper arm is built; obtaining a joint rotating instant heart motion, wherein the theorectical mechanics knowledge is adopted, and the motion center of the instant rotating motion of the forearm relative to the upper arm must be the point of intersection on the rigid body of the forearm not on the same vertical line of the three-point velocity directions. On the basis of the principle, the instant motion center of elbow joint anteflexion and rear protraction at the certain moment can be obtained. The method is easy to implement, a measuring point is bound to the human skeleton through a measuring point, calculation is easy, and measurement is accurate.