Using frequency-domain full waveform inversion (FWI) can obtain inversion results with high resolution and higher computational efficiency. Based on the traditional sequential single-frequency inversion strategy, a simultaneous multifrequency inversion strategy and a new objective function formula are given in this paper, and they are applied in FWI algorithm. This strategy can inverse all frequency components simultaneously and process weighted sum for each frequency in the frequency group. So high-frequency components can not dominate the inversion results and noise interference can be avoided. Three different models are used for validation in this paper. Experiments show that compared with the sequential single-frequency inversion strategy, the simultaneous multifrequency inversion strategy has better stability, accuracy and robustness. And with regard to profiles with sharp boundaries in the model, inversion results in the former strategy are closer to objective model.