Mass spectrometry imaging (MSI) is an emerging high-tech "photography" method combining mass spectrometry and image visualization technologies, which can simultaneously monitor the spatial distribution of multiple molecules in biological samples. In recent years, the characteristics of this technology have been used to visually study the distribution of drugs in hair, among which matrix-assisted laser desorption ionization-mass spectrometry imaging(MALDI-MSI) technology has been most widely applied in hair analysis. Based on the principle of MALDI-MSI technology, this paper discusses the key technical elements of MALDI-MSI technology applied to hair analysis and reviews the research achievements of MSI in hair analysis. It concludes that improving the ionization efficiency, resolution, sensitivity and stability of MALDI-MSI technology remains the future exploration direction, and simplifying data analysis and establishing databases will help promote MALDI-MSI as a routine analytical technique for hair analysis.