The invention discloses a grid-connected converter control method, comprising the following steps: step S1, establishing a model of a grid-connected converter, and calculating to obtain an output transfer function thereof; and step S2, determining a harmonic frequency range to be suppressed, setting corresponding PI parameters, initial temperature, virtual resistor initial value, virtual resistorresistance-value data range, iteration step and stop criterion; step S3, establishing an optimization model of the grid-connected converter by taking the filter effect function to be optimized as theobjective function, the virtual resistor resistance-value as the decision variable, the annealing function and the annealing end criterion as constraints; and step S4, performing optimizing and solving on the virtual resistor of the optimized model to determine the resistance-value of the virtual resistor. By applying the grid-connected converter control method, the grid-connected converter is enabled to have the output active power and the harmonic suppression function at the same time, the utilization ratio of the traditional grid-connected converter is improved, and the harmonic control cost of the grid is reduced.