The invention discloses a method for determining retrograde condensation oil saturability in a depletion development sandstone condensate gas reservoir reservoir. The method comprises the following steps: 1, obtaining a core of the actual reservoir, and cleaning and drying the core; 2, testing the gas phase effective permeability Kegi under different oil saturation Soi conditions, and determining the values of the parameter a and the pameter b in the formula Soi=aln (kegi) +b; 3, preparing formation fluid samples; 4, restoring the core to the original reservoir state; 5, lowering the pore pressure in the core, and recording the core inlet end pressure, the outlet end pressure and the core outlet end output air volume; 6, calculating the gas phase effective permeability Kfegi under the mean pressure condition in the core depletion process; 7, calculating the retrograde condensation oil saturability Soi in the sandstone condensate gas reservoir under different pressure conditions. The method is reliable in principle, simple and applicable, influence of porous media, water saturation and condensate oil flowing is taken into consideration comprehensively, and wide market prospect is achieved.