A control system (10, 20, 30) for a sewage treatment device comprising a single chip microcomputer, a lift pump connected to the single chip microcomputer and a gas pump connected to the single chip microcomputer, wherein the lift pump is configured to trigger a first switching signal, the single chip microcomputer is configured to acquire the first switching signal and regulate and control a running mode of the gas pump according to the first switching signal, and generate a second switching control signal for controlling the gas pump in order to perform aeration and backflow in the sewage treatment device; wherein the first switching signal comprises a starting signal and a shutdown signal, the second switching control signal comprises a delay start signal and a delay stop signal, and the single chip microcomputer is configured to regulate and control, according to the starting signal, a delay time of starting to run the gas pump, and generate the delay start signal; the single chip microcomputer is further configured to regulate and control, according to the shutdown signal, a delay time of stopping running of the gas pump, and generate the delay stop signal, the system further comprises the sewage treatment device connected to the lift pump and to the gas pump, wherein the sewage treatment device is configured to adopt a biological treatment method for sewage treatment, the gas pump is respectively connected to an aeration zone and a gas lifting zone in the sewage treatment device through two gas pipes, and is configured to regulate valves on the gas pipes to perform aeration and backflow according to the second switching control signal, wherein the lift pump is configured to pump sewage to the sewage treatment device. the lift pump is configured to trigger a first switching signal, the single chip microcomputer is configured to acquire the first switching signal and regulate and control a running mode of the gas pump according to the first switching signal, and generate a second switching control signal for controlling the gas pump in order to perform aeration and backflow in the sewage treatment device; wherein the first switching signal comprises a starting signal and a shutdown signal, the second switching control signal comprises a delay start signal and a delay stop signal, and the single chip microcomputer is configured to regulate and control, according to the starting signal, a delay time of starting to run the gas pump, and generate the delay start signal; the single chip microcomputer is further configured to regulate and control, according to the shutdown signal, a delay time of stopping running of the gas pump, and generate the delay stop signal, the system further comprises the sewage treatment device connected to the lift pump and to the gas pump, wherein the sewage treatment device is configured to adopt a biological treatment method for sewage treatment, the gas pump is respectively connected to an aeration zone and a gas lifting zone in the sewage treatment device through two gas pipes, and is configured to regulate valves on the gas pipes to perform aeration and backflow according to the second switching control signal, wherein the lift pump is configured to pump sewage to the sewage treatment device. the system further comprises the sewage treatment device connected to the lift pump and to the gas pump, wherein the sewage treatment device is configured to adopt a biological treatment method for sewage treatment, the gas pump is respectively connected to an aeration zone and a gas lifting zone in the sewage treatment device through two gas pipes, and is configured to regulate valves on the gas pipes to perform aeration and backflow according to the second switching control signal, wherein the lift pump is configured to pump sewage to the sewage treatment device.