High-thermal-conductivity mesophase pitch-based carbon fiber precursor and preparation method thereof

The invention relates to the technical field of carbon fiber production, and discloses a high-thermal-conductivity mesophase pitch-based carbon fiber precursor and a preparation method thereof. Comprising the following steps: carrying out flash evaporation treatment on petroleum heavy residual oil, conveying petroleum heavy residual oil residues at the bottom of a flash evaporation tower into a polymerization kettle, and adding aromatic oil into the polymerization kettle; carrying out high-temperature and high-pressure thermal polycondensation reaction in a self-pressurization manner; and pumping the polycondensed product into a high-precision filter for separation, conveying the product into a mesophase pitch reaction device, and further performing high-temperature normal-pressure polycondensation and nitrogen purging to obtain the high-purity spinnable mesophase pitch. And finally, performing melt spinning, pre-oxidation, carbonization, graphitization and the like to obtain the high-thermal-conductivity mes