Hydrophobic deep eutectic solvents are recognized as potential substitute of traditional toxic and harmful organic solvents and ionic liquids due to their simple preparation, low toxicity, high thermal stability and high biodegradability. Their hydrophobicity, highly adjustable physical and chemical properties and excellent solubility of organic and inorganic compounds can meet the needs of many industrial applications. Through the synergistic effect of electrostatic interaction, ions exchange and hydrogen bond, hydrophobic deep eutectic solvents achieved efficient separation, directional catalysis and modification of the target substances. This paper summarizes the structure composition and performance influencing factors of hydrophobic deep eutectic solvents, and review the application of hydrophobic deep eutectic solvents in separation and extraction, pollutant removal, biocatalysts, material modification and food safety detection. Hydrophobic deep eutectic solvents can achieve targeted regulation of the solvent properties by changing their structure composition, then highly selective extracts various target components in a wide pH range, and simplifies the process of catalysis and modification. Their high cycle stability greatly reduces the consumption of solvent, and shows great potential to replace traditional solvents in green chemical technology. However, the synergistic mechanism between the compositions of the hydrophobic deep eutectic solvents is not clear, it is necessary to further to clarify their function mechanism in order to achieve the precise customization and efficient application of the hydrophobic deep eutectic solvents.