The invention discloses an insulator recognition and fault diagnosis method based on an infrared image. The method comprises the following steps of A, performing photographing on an insulator and performing image recognition for differentiating different insulators; and B, analyzing temperature characteristics of the different insulators in displaying in the image, and determining the insulator with the abnormal temperature characteristic as a faulted insulator. The insulator recognition and fault diagnosis method can settle defects in prior art and furthermore has advantages of high suitability of automatic checking in a complicated environment and low error determining rate.