In our previous study, the incoherent combined microwave sources possess a higher water heating rate than a single microwave source. This novel discovery may blaze a new trail in the pursuit of energy conservation. In this paper, a particular orthogonal microwave field device was designed to quantitatively study the effect of incoherent combined microwave heating on 17 solvents. Experimental results indicate that the solvents irradiated with incoherent combined microwaves absorb more microwave energy and experience a faster temperature rise. The multiphysics simulations of water with different microwaves show that the higher heating rate is not caused by the improvement of heating uniformity. In this regard, molecular dynamics simulations of ethanol under the irradiation of incoherent microwave electric fields with perpendicular polarization directions were carried out. The molecular dynamics simulations demonstrate that the main reason for this effect is the higher collision frequency of molecules with incoherent microwave electric fields. This study demonstrates a novel effect of incoherent combined microwave heating and contributes to the development of efficient microwave heating for industrial applications.