The extraction of nitrogen-containing heterocyclic basic compounds (NHBCs) from coal tar is necessary to promote the clean and efficient utilization of coal resources and the protection of environment.This paper developed three green and efficient deep eutectic solvents (DESs) for the separation of NHBCs.The hydrogen bond donors (HBDs) and hydrogen bond acceptors (HBAs) composing the DESs were screened by thermodn. properties of selectivity, solvent capacity, and performance index calculated by COSMO-RS model.The extraction performance of the selected DESs was assessed by exptl. determination of phase equilibriumThe DES ([TEAB:2MA]) composed of tetraethylammonium bromide (TEAB) as HBA and malonic acid (MA) as HBD exhibited the best extraction performance for pyridine.The influence of key parameters on the extraction efficiency, such as agent-oil mass ratio, extraction time, extraction temperature, standing time, and initial pyridine content, were conducted.Also the reusability of DESs under the optimal exptl. parameters was investigated.Finally, the quantum chem. (QC) calculations and FT-IR anal. were used synergistically to provide microscopic insights into the extraction mechanism.This work provides a valuable reference for the development of new processes for the extraction of NHBCs from coal tar.