An elevator door control system, an elevator system, and an elevator door control method based on to-be-carried object grouping identification. The elevator door control system includes one or more three-dimensional sensors, arranged to capture three-dimensional data of to-be-carried objects in an elevator waiting region, wherein the three-dimensional data includes depth data; a data processing device, communicating with the three-dimensional sensor, and configured to receive and process the three-dimensional data, to provide grouping data of one or more groups obtained according to correlations between the to-be-carried objects and position data of each to-be-carried object in the elevator waiting region; and a control device, connected to an elevator door, communicating with the data processing device, and configured to control operation of the elevator door according to the grouping data and the position data.