With constantly developing of social scientific theory, present correlation theoretical researches are urgently in need of natural science, modern science and technology melting, in the hope of deeply solving relative problems. This paper targeted sports movement horizontal bar event, taking athletes’ downward swinging as examples, analyze athletes’ status, establish mathematical model, and implement discussion and researching on relative problems. According to body swaying technical features, multi rigid body model, then utilizes dynamics method, corresponding dynamic equation deducing human race swaying. Results show giants turn or grip change motion is more beneficial in 40°-50°or 310°-320°.