The invention discloses a preparation method of terpene resin. The preparation method specifically comprises the following steps: in the process of loading a catalyst into a molecular sieve, dispersing by ultrasonic waves, putting the loaded molecular sieve into a tubular reactor, adding a reaction raw material, a solvent and a coupling agent into the tubular reactor, controlling reaction temperature to 70 to 80 DEG C, connecting a water washing machine at an outlet of the tubular connector to wash a product by water, sending the water-washed product into a distilling device, and distilling, so as to obtain the solvent and the terpene resin; returning the solvent back into the system to recycle. The preparation method has the advantages that the reaction speed is accelerated, the conversion rate is improved, and the continuous reaction can be performed.