Through analyzing commonly used velocity planning algorithm in CNC machining, aiming at the CNC machine tool vibration due to unsmoothed velocity, acceleration and jerk during acceleration/ deceleration stage, an quartic polynomial acceleration and deceleration control model was proposed. The derived steps of the quartic polynomial velocity equation were also given in detail. Then a parametric curve interpolation algorithm based on quartic polynomial velocity equation was proposed. The algorithm can provide smooth velocity curve, acceleration curve and jerk curve and relieves intense vibration in high speed CNC machining. Simulation experimental results show that the quartic polynomial velocity planning algorithm can realize flexible acceleration/deceleration control and implement high-quality CNC processing.