The characteristic X-ray imaging technology is proposed to obtain the latent fingerprint. To obtain the latent fingeprint, the X-ray fluorescence spectrometer based on the capillary focusing X-ray lens (CFXRL) and the laboratory X-ray source is designed. The focal spot diameter of CFXRL and the gain of CFXRL are 32.2 μm and 2940 respectively. This is helpful in detecting the characteristic X-rays of the elements in latent fingerprint efficiently, with high spatial resolution. Characteristic X-ray imaging technology can judge the substance contacted by the fingerprint owner before leaving it. This is also useful in forensic sciences. It is proved that the CFXRL has potential applications in obtaining the latent fingerprint.