Disclosed is a heating system controller. The heating system controller comprises a cabinet body. The cabinet body is provided with a touch display screen, a radio port, a recommended standard (RS) 485 port and a power port. A function module which composes a control system is installed in the cabinet body, an input/output (IO) module is installed outside the cabinet body, and the IO module is connected with a bus port module of the control system in a plugged mode. A miniature industrial control main machine is utilized for a main controller and a user wiring port is provided with a plurality of module sockets. Due to the fact that modularized assembly is utilized, a worker can conveniently add or replace a module and does not need to adjust the interior of the heating system controller. Therefore, the heating system controller is low in use cost and maintenance cost, and simple in upgrade or change. Due to the fact that the touch display screen is arranged on the cabinet body, a human-machine operation interface is friendly and easy to use, and promotional value is great.