The invention discloses a synchronous data acquisition system used in a wind tunnel based on stable dynamic pressure control. The data acquisition system comprises a pressure sensor, a pressure acquisition system, an aerodynamic force balance unit, an aerodynamic force acquisition system, a standard pressure source, an industrial personal computer (IPC), a stable dynamic pressure sensor, an accuracy control device, an aerodynamic parameter system and a motor fan, wherein, the pressure sensor measures the pressure in the low-speed wind tunnel and transmits the measured pressure value to the pressure acquisition system; the aerodynamic force balance unit measures aerodynamic force on an experimental model and outputs the measured aerodynamic force value to the aerodynamic force acquisition system; the standard pressure source respectively calibrates the pressure sensor, the pressure acquisition system and the stable dynamic pressure sensor so as to obtain calibration factors, the calibration factors are transmitted to the IPC so as to obtain a controlled process mathematical model for stable dynamic pressure control, and then the controlled process mathematical model is transmitted to the accuracy control device; the accuracy control device drives the pressure acquisition system, the aerodynamic parameter system and the aerodynamic force acquisition system to perform synchronousdata acquisition; the stable dynamic pressure sensor acquires variation of a flow field in the low-speed wind tunnel, and then the variation value is transmitted to the IPC; and the IPC controls the motor fan to rotate. The data acquisition system disclosed by the invention has the advantages that manpower is saved, high-accuracy data can be obtained, the operating method is simple and practical,the cost is low and the application prospect is wide.