The invention provides an acoustic insulation loss calculation method and system. The calculation method comprises the steps of performing geometric model building and mesh division on an acoustic insulation part, an anechoic chamber and a reverberation chamber in sequence according to structural parameters and a test environment of the acoustic insulation part to obtain a structural mesh model and an acoustic mesh model for acoustic insulation loss calculation of the acoustic insulation part; according to material parameters of the acoustic insulation part, the anechoic chamber and the reverberation chamber, performing material attribute definition on the structural mesh model and the acoustic mesh model, establishing an envelope surface of the acoustic mesh model, and obtaining a finiteelement analysis model; according to preset test requirements of the acoustic insulation part, setting contact surfaces of the structural mesh model and the acoustic mesh model in the finite element analysis model as acoustic-solid coupling surfaces, and performing constraint condition application and acoustic source setting on the structural mesh model; and performing acoustic vibration couplingcalculation on the finite element model to obtain a function G(f) between acoustic insulation loss G of the finite element model and the frequency f of acoustic source vibration.