The work aims to improve the detection speed and accuracy of the packaging coil image to achieve the rapid online detection. A few standard image samples were spliced beforehand. The extended image samples obtained were taken as the master mask of the variable template. A simplified image geometric moment in the central region of the image sample to be detected should be calculated first during the detection, and the best matching position was searched in a section of the foregoing template. Then, with such position as the center, the area marked off on the template image having the same size as the image to be detected was regarded as the variable template. Finally, the image subtraction method was implemented to realize the detection and recognition of defects. The two-order simplified geometric moments could reduce the operand effectively, and the dynamic template could significantly improve the detection speed of the coil image. The proposed algorithm was tested with the packaging coil carrier tape of the electronic components as the detected objects. The detection speed was no less than 2 m/s under the condition of higher resolution. The proposed algorithm can meet the requirements of rapid online detection of packaging coil, and provide certain reference significance for the detection speed of uncertain-phase image.