The invention belongs to the computer-aided machining related technology field, and discloses a five-axis B-spline cutter path arc length parameterization method based on the cutter axis stability. The method comprises the following steps that 1, cubic Bezier curves are established between every two adjacent cutter location points; 2, the cubic Bezier curves between every two adjacent cutter location points are subjected to isoparametric sampling to obtain cutter location point spline sampling points; 3, arc length parameters of the cutter location point spline sampling points are calculated to serve as arc length parameters of target sampling points of a six-dimensional space, and cutter axis vectors and arc length parameters of the cutter location points are calculated; 4, cutter axis point spline sampling points corresponding to the cutter location point spline sampling points are calculated, and then the target sampling points of the six-dimensional space are obtained; and 5, a target function is established according to the target sampling points of the six-dimensional space and the arc length parameters, and a five-axis B-spline cutter path subjected to nearly arc length parameterization is solved accordingly. According to the method, the speed fluctuation during machining is reduced, and the machining quality and efficiency are improved.