The effect of the solvent deasphalting (SDA) process of vacuum residue (VR) blending with coal tar (CT) was studied, and the experimental conditions were optimized. The results revealed that the SDA process was improved by blending with coal tar. The yield of deasphalted oil (DAO) from VR blended with 10% CT was 2.02 wt% higher than that obtained from VR alone. The contents of nickel and vanadium decreased by 5%, and the sulfur content also decreased, whereas the contents of carbon residue, and nitrogen remained unchanged. Components such as alkanes and low-condensation aromatics were easily extracted into DAO, leading to an increase of its yield and quality. The viscosity and colloid stability of VR declined after being blended with CT. Furthermore, the structures of VR and CT were characterized, and their structural models were proposed. Thus, their solubility parameters were calculated. According to dissolved balance theory, the mechanism of how the blended CT improved the SDA process was analyzed based on the test results of the surface tension of the extraction and the analysis of the average molecular structure parameters of DAO.