The work aims to study a new method to analyze the synergistic effect between inhibitors. The amorphous cell module in material studio 7.0 software was used to construct object. In different systems, discover module was employed for optimization and calculation and carry out FFV test with water molecule as the probe to obtain FFV through simulation and calculation. Then, the change rate of FFV was adopted to predict the synergistic effect between inhibitors and the correctness of the method was verified by traditional method. From the simulation result of FFV, MTIAS and AB2N had synergistic effect in CO2 system. When these two components were combined in accordance with the mole ratio of 3∶2, FFV was the smallest, FFV had the maximum change value D, the best synergistic effect and the highest inhibition efficiency, while MTIAS and CPQA had no obvious synergistic effect. In CO2/H2S system, when MTIAS and CPQA were combined with a mole ratio of 4:1, FFV was the smallest, D was the largest, the synergistic effect was the best, and the inhibition efficiency was the highest. However, when MTIAS and CPQA were combined with a mole ratio of 1∶4, there was obvious antagonistic effect. MTIAS and AB2N had no obvious synergistic effect. The results of weight-loss method and the polarization curve test were in agreement with the above results. It is a fast and effective method to predict the synergistic effect of inhibitors by FFV of inhibitor film.