There are edge blur and noise residues in the course of edge extraction for infrared image by existing edge detection algorithm.In response to this phenomenon,an infrared contour extraction algorithm based on ants search and edge detection is put forward.The correlation factor of the image is introduced to classify image signals based on the wavelet transform correlation between each high frequency sub band.The edge detection algorithm based on ant colony algorithm is used to extract the weak edge signal,then small noise signals are removed and the weak edge signals are protected.Experimental results show that the results are basically consistent with the expected results.It has a good anti interference ability and edge protective effect in different complex background infrared images.