An aspect of the disclosure includes a communication system and a communication method using reconfigurable intelligent surface and a reconfigurable intelligent surface device. The communication system includes at least one base station, a reconfigurable intelligent surface device, and a control at one least device. The at least one base station respectively transmits at least one beam. The reconfigurable intelligent surface device is coupled to the at least one base station, and measures the at least one beam of the at least one base station to obtain signal measurement results associated with each of the at least one base station. The control device is coupled to the at least one base station. The control device groups the at least one base station and the reconfigurable intelligent surface device into at least one group according to the signal measurement results associated with each of the at least one base station.