The invention provides a boiler system. According to the system, automatic control can be performed according to the amount of steam generated by a boiler and the amount of water input to the boiler, the boiler is subjected to sewage discharge periodically, the sewage discharge speed is kept unchanged, a central diagnosis monitor automatically sets the sewage discharge speed according to the ratio of the mass of the steam to the mass of the water input to the boiler and is in data connection with a cloud server so as to transmit monitored data to the cloud server, the cloud server is connected to a client side, and the client side can obtain the monitored data through the cloud server, manually inputs the sewage discharge speed according to the obtained data, transmits the data to a monitoring and diagnosing controller through the cloud server and manually adjusts the sewage discharge amount through the monitoring the diagnosing controller. The system has the advantages that the input water quantity and the generated steam quantity of each boiler are monitored in real time, the dynamic ratio relation of the input water quantity and the generated steam quantity is obtained, the sewage discharge amount of the boiler can be automatically calculated according to the dynamic ratio relation, the sewage discharge speed can be adjusted according to the sewage discharge amount, the operation condition of a boiler sewage discharge system can be timely mastered by the client side, the sewage discharge parameters can be adjusted timely through the client side, and a large amount of heat energy waste caused by faults of the boiler sewage discharge system can be prevented.