The invention discloses a two-source two-energy linear security inspection CT device and a detection method thereof, wherein a ray generator and a data collector are connected with a control and image processing system, the ray generator comprises a high energy ray generator and a low energy ray generator, a high energy data collector and a low energy data collector are arranged correspondingly with the high energy ray generator and the low energy ray generator, the high energy ray generator and the low energy ray generator are horizontally arranged at the side surface of an object transmitter, which rays are cornered of 90 degrees. The invention can effectively recognize the matters of similar densities and different atom numbers, can quickly and accurately recognize suspected matters aswell as obtain the sectional image and the three-dimension image of the suspected region of the object. The two-source two-energy linear security inspection CT device has simple structure and low production cost. The invention adopts reconstruction and fusion methods to analyze data and can effectively recognize the dangerous materials of objects.