The invention discloses an electromechanical driving system for a fire extinguisher. The electromechanical driving system comprises a chargeable lithium battery, a DC (direct current) motor and a diaphragm pump, wherein the DC motor is connected with the output terminal of the chargeable lithium battery; the diaphragm pump is connected with the output terminal of the DC motor; the capacity of the chargeable lithium battery is larger than 3200 mAh; the working voltage of the DC motor is 12 V; the diaphragm pump is made of one or more of plastic, aluminium alloy, cast iron and stainless steel. Through the adoption of the manner, the electromechanical driving system for the fire extinguisher, disclosed by the invention, has the advantages of scientific structure, novel appearance, reasonable configuration, advanced function, electric driving, coherent liquid feeding, constant-pressure working, safety, reliability, economy, practicality and the like, and has a broad market prospect of the popularization of electromechanical driving systems for fire extinguishers.