The invention relates to an elevator operation control method, device and system and a storage medium. The control method comprises the steps that the expected loading capacity for elevator-needing users of a to-be-reached elevator at the current floor is calculated according to exploratory data of a millimeter wave sensor in an elevator waiting hall of the current floor; the residual loading capacity when the to-be-reached elevator reaches the current floor is calculated according to exploratory data of a millimeter wave sensor in the to-be-reached elevator; and when a difference value between the expected loading capacity and the residual loading capacity exceeds the difference value threshold, an available elevator is dispatched to the current floor from elevators except the to-be-reached elevator. By means of the method, in the process of waiting the to-be-reached elevator to reach the current floor, when the residual loading capacity of the to-be-reached elevator is insufficient,the available elevator is dispatched in advance to the current floor, so that elevator dispatching time consuming can be reduced, the passenger elevator waiting time is shortened, and the elevator taking efficiency is improved.