1. A sectional image recognition method applied in a zonal fingerprint recognition device having a memory with small storage capacity, comprising: Step a: setting an image selection frame; Step b: capturing a fingerprint image block of a size corresponding to the image selection frame; Step c: executing a minutiae conversion program on the fingerprint image block to generate a minutiae block image corresponding to the fingerprint image block; Step d: repeating Step b and Step c until all fingerprint image blocks corresponding to the minutiae block images are obtained; Step e: executing an image stitching program on the corresponding minutiae block images according to an acquisition sequence of the fingerprint image blocks, so as to generate a minutiae image corresponding to the fingerprint image blocks; Step f: executing a fingerprint recognition program on the minutiae image; and Step g: according to a recognition result acquired by the fingerprint recognition program, sending, by the zonal fingerprint recognition device, a corresponding response message.