The invention discloses a method for detecting the azimuth of a damaged oilfield downhole casing. In the method, a casing detector (1) for detecting a casing is connected with a gyroscopic clinometer (2), or an azimuth measuring mechanism (3) is mounted in the casing detector (1); the position of a probe of the casing detector (1) can be calculated by measuring the inclination of the gyroscopic clinometer (2) or the position of the azimuth measuring mechanism (3), and thus, the specific azimuth of the damaged position of the casing can be calculated. In the invention, the specific azimuth of the damaged position of the casing can be visually and precisely detected, and the method has the characteristics of high detection accuracy and less detection error and is simple and convenient to operate. The invention perfects the detection means of the downhole casing and provides important foundations for oilfield downhole analyses. The invention is applicable to the azimuth test of all downhole detection parameters.