The present invention provides a grid-connected inverter control method based on time-lag robustness model algorithm. A grid-connected inverter time-lag robustness model is built, the influence caused by a dead-time effect is equivalent to a nondeterminacy interference source having an upper bound to bring into the grid-connected inverter time-lag robustness model, and the influence of the time-lag and the dead-time effect on the output fundamental current deviation and the output current harmonic total harmonic distortion of the grid-connected inverter is considered. The time-lag robustness optimal control theory is employed to calculate the optimal parameters of the grid-connected inverter control rule so as to obtain the optimal control rule of the grid-connected inverter, allow the output current total harmonic distortion of the grid-connected inverter to be decreased and allow the steady accuracy to be the highest.