The present disclosure relates to a photoresist composition, a method for preparing the same, and a patterning method. The photoresist composition includes: 1 wt % to 10 wt % of a photosensitizer; 10 wt % to 20 wt % of a phenolic resin; 0.1 wt % to 5.5 wt % of an additive; and 75 wt % to 88 wt % of a solvent, based on the total weight of the photoresist composition, in which the photosensitizer includes: 20 wt % to 70 wt % of a first photosensitive compound represented by formula (1), 20 wt % to 70 wt % of a second photosensitive compound represented by formula (2), and 1 wt % to 35 wt % of a third photosensitive compound represented by formula (3), based on the total weight of the photosensitizer. The photoresist composition of the present disclosure simultaneously guarantees high resolution and high sensitivity, and can meet actual production requirements.