The invention discloses a geometric precision and linking speed optimization five-axis linkage smooth interpolation method, and the method comprises the steps: (1), obtaining a corresponding translation axis path and a rotating axis path according to a five-axis linkage tool path in a given machine tool coordinate system; (2), defining fairing parts and linear parts of the translation axis path and the rotating axis path; (3), carrying out the modeling of a comprehensive fairing error according to the circular arc radiuses and feed speed of the fairing parts of the translation axis path and the rotating axis path; (4), taking linking speed optimization as the target, and calculating the circular arc radiuses and feed speed of the fairing parts of the translation axis path and the rotating axis path; (5), carrying out the interpolation according to a time segmentation method. The method can solve a problem that an interpolation period is not an integral without precise given path linking points, also can avoid the constraint on the feed speed from a path length, can obtain a higher feed speed through introducing an controllable interpolation error, and improves the machining efficiency.