The invention discloses an integrated control system based on semi-active balancing. The system comprises a mechanical spring, a power hydraulic cylinder, a rate gyroscope, and a DSP (digital signal processor) controller. The mechanical spring is used for compensating part of unbalanced force of a barrel. The power hydraulic cylinder is used for balance compensation for system unbalanced force and external disturbance and also used for high-precision positioning control for the barrel. Two pressure sensors are used for detecting pressure difference between upper and lower cavities of the power hydraulic cylinder and establish a pressure control procedure with a servo control part. A rotary transformer is used for measuring the position of the barrel relative to a carrier. The rate gyroscope is used for measuring turning speed of the barrel to provide speed information for high-precision fast positioning control. The DSP controller calculates controlled quantity in real time to allow for high-precision positioning control of the barrel according to the values measured by the pressure sensors, the rotary transformer and the rate gyroscope. The integrated control system based on semi-active balancing is widely applicable to fast, accurate and stable control of gun barrels or like structural mechanisms.