The ultra-trace UV-visible spectrophotometer is a full-wavelength ultra-trace UV-visible spectrophotometer. The trace detection mode can be used to detect nucleic acids, micronucleic acid arrays, pure protein detection, labeled protein detection, protein quantitative detection, microbial cell culture detection, and Conventional full-wavelength scanning, cuvette detection mode can measure nucleic acids, proteins, microbial cell culture and kinetic detection.