A display device, display panel and manufacturing method thereof, where the display panel includes an array substrate including a plurality of thin film transistors, a pixel define layer disposed on the array substrate, and an organic light-emitting structure which is surrounded by the pixel define layer and of a top emission structure. The display panel further includes: a light blocking layer disposed between the array substrate and the pixel define layer and configured to prevent light passing through the pixel define layer from irradiating on the thin film transistor. By disposing the light blocking layer between the array substrate and the pixel define layer, light passing through the pixel define layer may be prevented from irradiating on the thin film transistor in the array substrate. Therefore, leakage current generated by the thin film transistor due to optical excitation may be reduced, thereby improving stability of the thin film transistor.