The invention discloses a roundness error evaluating method based on variable-interval reverse chaos optimization. By virtue of the random search increasing capability of chaotic mapping, the escape local extremum increasing capability of a reverse optimization strategy and the optimization space reducing capability of a variable-interval reverse optimization strategy, rough searching, fine searching and variable-interval reverse optimization are sequentially performed; along with increase in the number of iterations, an optimized circular center variable interval constantly decreases, constantly tends to an optimal solution direction, and finally achieves global optimization, so that the robustness is relatively strong. By the variable-interval reverse optimization strategy, by virtue ofa reverse solution of the currently searched optimal solution Xmin, the diversity of an algorithm evolution process is increased, the position of a global optimal solution of the algorithm can be explored according to the maximum efficiency, and algorithm evolution in the interval conversion process is avoided from entering a local extremum point; in the strategy optimization process, the forwardoptimal solution Xmin is used for improving the convergence speed, and the reverse optimal solution is used for expanding the searching range, so that the solution jumps out of a local optimal solution and tends to the global optimal solution X*.