The cutting speed of highspeed CNC machine tool is more than 60 m/min and the acceleration is more than 2g. For small curvature and discontinuous tangent machining, it is easy to cause bump peaks, produce mechanical vibration, reduce cutting quality and shorten the life of equipment. At present, the discontinuity of tool path can be eliminated by path smoothing technology, but this technology is limited to linear tool path. A new path smoothing method based on chamfer of double gyration curve was proposed. By this method, any straight line and arc path could be converted into curvature continuous path, and interpolation was simplified by parameterizing the arc length of the path. According to the test of NC laser cutting machine tool, smooth corner can be fitted between arc and arc or between arc and straight line. Comparing with Bessel curve roundness, this method improves feed speed, shortens cycle time and smoothes curvature profile.