Automatic dosing system and method for railway sewage

The invention relates to an automatic dosing system and an automatic dosing method for railway sewage. The system comprises a medicine storage box, a grinding machine, a dissolving tank, a water inlet pipe of the dissolving tank and an air floatation tank, wherein the medicine storage box is connected to the grinder through a connecting pipe, the grinder is connected to the dissolving tank through a grinder medicine outlet pipe, and the dissolving tank is connected to the air floatation tank through a liquid medicine outlet pipe; inductors or actuators are arranged on the medicine storage box, the grinding machine, the dissolving tank, the water inlet pipe of the dissolving tank and the air floatation tank and are connected into a first PLC terminal controller; wherein the inductors send induction parameters to the first PLC terminal controller, and the first PLC terminal controller gives an alarm by comparing the induction parameters with a preset threshold value and controls the actuators to operate. The sy