Preparation method of petroleum-based high softening point spinning pitch

The invention discloses a preparation method of petroleum-based high softening point spinning pitch and belongs to the technical field of spinning pitch. The preparation method includes the steps of preheating ethylene tar, performing wiped film vaporization to remove light components at the temperature of 220-280 DEG C under the vacuum degree of 80-120Pa so as to obtain ethylene tar pitch, transferring the ethylene tar pitch into a reactor, heating to 330-360 DEG C, performing constant-temperature thermal polycondensation to obtain ethylene tar pitch softening at 200-225 DEG C, performing wiped film vaporization to the ethylene tar pitch to remove part of the light components at the temperature of 340-370 DEG C under the vacuum degree of 80-120Pa so as to finally obtain spinning pitch which softens at 270-285 DEG C. The preparation method has the advantages of continuity in operation, simplicity in process flow, high controllability and suitability for industrial production. The prepared spinning pitch is high in coking value, excellent in spinning performance, and available for continuous spinning more than 10000m in length.