The invention discloses a method for detecting high solid content and asphaltene content of coal liquefaction oil. The method comprises the following steps: (1) dissolving a coal liquefaction oil sample in n-heptane, and then carrying out ultrasonic and heating treatment on the mixture; (2) standing a product obtained in step (1), then filtering, and reserving filter residue for standby; (3) placing the filter residue in a Soxhlet extractor, carrying out reflux and vacuum extraction using n-heptane until a liquid flowing out of a siphon of the Soxhlet extractor is totally colorless, thereby obtaining a n-heptane insoluble substance; (4) placing methylbenzene in a container, carrying out reflux and extraction on the n-heptane insoluble substance obtained in step (3) until the liquid flowing out of the siphon of the Soxhlet extractor is totally colorless, then drying a product in the container to obtain asphaltene, and seeing the descriptions for quality record; and (5) calculating to obtain the asphaltene content. According to the method for detecting the high solid content and asphaltene content of the coal liquefaction oil, the experimental result is accurate for the coal liquefaction oil that is high in solid content and asphaltene content, the repeatability and reproducibility of the experimental result are good, and the reliability of the experimental result is high.