The invention provides an automatic control boiler system. The system comprises a monitoring diagnosis controller and a boiler; a steam drum comprises a water quality analyzer; the water quality analyzer comprises a PH value testing unit for measuring the PH value of water in the steam drum; the water quality analyzer is in data connection with the monitoring diagnosis controller to receive measured PH data; the boiler termly discharges pollutions; the pollution discharge time is kept invariable; and a central diagnosis monitor automatically sets a pollution discharge speed according to the measured PH value to automatically control the pollution discharge quantity. Through real-time monitoring of the PH data of each boiler, the pollution discharge quantity of the boiler is automatically calculated according to a dynamic proportional relation; the pollution discharge speed and the pollution discharge time are adjusted according to the pollution discharge quantity; a client can timely master the operation conditions of a boiler pollution discharge system; and pollution discharge parameters are adjusted timely through the client to prevent a lot of heat energy wastes caused by faults of the boiler pollution discharge system.