Abstract: This paper presents an image matching approach based on triangle constraint which can control the error propagation during the matching process.Firstly,this approach detects the triangles that may have been mismatched or located in changed regions.In the following process,those triangles are assigned with a lower priority;therefore,it is effective to control the error propagation during the matching process.Experiments show that error propagation in the matching process is effectively controlled by this approach and the matching precision is improved.