The invention provides a wind power plant PI controller parameter setting method and device, and the method comprises the steps: carrying out the orthogonal test of the parameters of each PI controller of a wind power plant, and obtaining the value range of each parameter; initializing parameters based on the value range; on the basis of the initialized parameters, adopting a particle swarm optimization algorithm to determine the setting result of the parameters. The optimization effect obtained through the method and the performance of the PI controller are good, the iteration convergence speed is greatly increased, and the situation of falling into a local extreme value is avoided. The chaotic orthogonal particle swarm optimization algorithm adopted by the invention can reasonably determine the optimization range of each parameter, the optimization direction and the corresponding weight, meanwhile, the initial value quality is improved, the number of iterations is effectively reduced, a better compensation effect is achieved on the terminal voltage of the common connection point between the wind power plant and the power grid, and meanwhile the output characteristic based on thedoubly-fed asynchronous wind driven generator is effectively improved.