Abstract: The Global Navigation Satellite System (GNSS) and inertial navigation system (INS) are widely used in fields such as vehicles and drones. However, GNSS receivers are susceptible to deceptive signals. Therefore, this paper proposes a consistency deception detection technique using INS observations. Inertial devices have the characteristics of being less susceptible to deceptive signal interference and prone to cumulative errors. By alternately feeding back estimated errors in an open-closed loop manner, a GNSS/INS integrated navigation system is constructed. During the open-loop period, a deception detection window is established, and the consistency between the statistical detection measurements of the inertial device, acceleration, and angular velocity obtained from GNSS is evaluated to determine the presence of deception. Experimental results demonstrate that with a window time of 70 s, the detection probability reaches 99.2% while the false alarm probability is 5.2%.