Disclosed in embodiments of the present disclosure are a display panel, a preparation method thereof, and a display device. A display panel having a display area and a non-display area includes: a base substrate; an auxiliary electrode in the non-display area; a passivation layer disposed on a side of the auxiliary electrode facing away from the base substrate, having a first opening in the non-display area, in the first opening, an accommodating space is formed between the passivation layer and the auxiliary electrode, the accommodating space exposes part of the auxiliary electrode; an orthographic projection of the passivation layer on the base substrate covers an orthographic projection of the accommodating space on the base substrate; a cathode layer disposed on a side of the passivation layer facing away from the base substrate, having a connecting portion in the accommodating space, the connecting portion being connected to the auxiliary electrode.