This work was aimed to prepare modified polyvinyl alcohol (PVA) films with antifungal effects by adding citric acid (CA) to PVA. By adjusting the heating time, heating temperature, stirring speed and other parameters, the regularity of the preparation of the modified PVA colloid was found. And the acidic antifungal modified PVA films were prepared by flow-casting method. The physical properties were studied using the optical and mechanical parameters, and the antifungal effects were studied using the preservation experiment of semi-dried fish. The acidic antifungal modified PVA films obtained all had good optical and mechanical properties. For the antifungal effects in preservation of semi-dried fish during storage period, the modified PVA films all showed better antifungal effects than the control group, among which the antifungal capacity of the films modified with 2% CA was the best. The modified CA-PVA films had certain regularity in its preparation process and showed good antifungal effects in packaging semi-dried fish.