The invention relates to a transparent conducting thin film with enhanced thermal stability and a preparation method and application thereof. The transparent conducting thin film consists of a substrate, a first semiconductor layer, a silver alloy layer and a second semiconductor layer sequentially from bottom to top; according to the silver alloy layer, metal silver is combined with aluminum, zinc, titanium, copper, magnesium, nickel, rare earth elements or chromium to form a bi-element silver alloy layer or a multi-element silver alloy layer. The transparent conducting thin film provided by the invention can be used for photoelectric devices, such as organic light-emitting devices (OLEDs), organic solar cells and perovskite batteries; furthermore, on the basis of improving the thermal stability of the photoelectric devices, the dose of the photoelectric devices on a silver material per unit area can be reduced, device cost can be beneficially controlled, resources are saved; and the transparent conducting thin film also can be applied to magnetic shielding, special functional window coatings, transparent heat preservation building glass and the like.