A construction method and system for a visible near-infrared spectrum dictionary is provided. The method includes: constructing a four-primary color chromaticity cone by using normalized spectral response curves of four primary colors of a visible light camera as spectral basis functions; performing weighted combination on the spectral basis functions and forming an initial visible near-infrared spectrum dictionary; acquiring points on the four-primary color chromaticity cone on the basis of the initial visible red infrared spectrum dictionary according to different spectral resolutions and performing discretization, and forming words in the initial visible near-infrared spectrum dictionary; clustering chromaticity coordinates corresponding to the words into different groups, performing weighted combination on multi-scale spectral response curves corresponding to different group types, generating phrases or sentences in the dictionary, and generating a final visible near-infrared spectrum dictionary. The visible near-infrared spectrum dictionary can support a novel computational spectrometry imaging spectrometer.