The present invention provides an AMOLED backplane structure and a manufacturing method thereof. In each sub-pixel, a TFT substrate (TS) includes a corrugation structure (4) formed in an area corresponding to an opening (71) of a pixel definition layer (7). The corrugation structure (4) includes a plurality of raised sections (41) and a recessed section (42) formed between every two adjacent ones of the raised sections (41). An upper surface of a portion of the planarization layer (5) and a portion of a pixel electrode (6) that correspond to and are located above the corrugation structure (4) include curved surfaces corresponding to the corrugation structure (4). The AMOLED backplane structure helps ensure the planarization layer (5) is smooth and free of abrupt change sites and also makes the pixel electrode (6) in a form of a curved surface to increase an effective displaying surface, extend the lifespan of the OLED, reduce difficulty of manufacturing, and improve resolution.