The invention provides a locomotive air source purification device controller which comprises a box body and a circuit device. The circuit device comprises an interface, a power supply, a first indicator lamp, a second indicator lamp, an alarming indicator lamp and a control circuit board, wherein the interface, the power supply, the first indicator lamp, the second indicator lamp and the alarming indicator lamp are installed on the box body, and the control circuit board is fixedly installed in the box body. The control circuit board is provided with a power circuit, a signal input circuit, a single chip microcomputer control circuit, a first output control circuit, a second output control circuit, a first execution circuit, a second execution circuit and an alarming circuit. The power circuit provides a working power supply for the other circuits. The signal input circuit, the first output control circuit and the second output control circuit perform isolation through a photoelectric coupler and performs shaping and inverting through a Schmitt trigger. Starting signals of an air compressor of a locomotive are processed by the single chip microcomputer control circuit and then output by the first output control circuit and the second output control circuit, and afterwards, the first execution circuit and the second execution circuit control two electric pneumatic valves on the locomotive so as to control two drying and purifying towers to work. The locomotive air source purification device controller is strong in anti-interference capacity, high in time control precision and high in working reliability.