The invention discloses a coordination control method for a reactive voltage in a wind farm, and belongs to the technical field of coordination control over reactive voltages in wind farms. The method comprises the steps that an SVC-containing double-fed wind farm reactive coordination optimization model is built by considering cooperation of a double-fed induction generator and an SVC on the basis of analyzing the reactive output capacity of the double-fed induction generator and the SVC device according to a basic node voltage stability index, a margin index of reactive generation equipment and a target function that the node voltage is most stable and the reactive margin in the wind farm is highest, and finally resolving is conducted by adopting an improved chaos ant colony optimization algorithm to achieve optimum control. According to the coordination control method, the reactive margin in the wind farm is higher while the local network voltage level of the wind farm is increased, the condition that all ant colonies are located at the optimal solution is adopted as the algorithm finishing condition, unnecessary calculation is avoided as far as possible, and the convergence rate of the algorithm is increased.