The invention relates to a gas line drag reduction agent and a preparation method thereof, relating to the technical field of the composite of high-molecular compound and
piping systems. The drag reduction agent consists of
carbon bisulfide, hydrazine
hydrate and
long chain acid, the mol ratio of which is 1.8:1:1 to 2.2:1:1. The preparation method comprises the following steps: step one, CS2 is taken according to proportional quantity, dripped into the mixed liquor of the hydrazine
hydrate and water with proportional quantity under agitation, reflowed for certain time in the temperature range of 90 to 95 DEG C, then cooled for 30 to 60 minutes in
ice water bath and pumped and filtered, the
mother liquor continues to react for two times, products of the third time are merged, washed by using
ethanol and
ether sequentially, and recrystallized by using boiling water so as to obtain symmetrical diaminothiourea clear
crystal; and step two, symmetrical diaminothiourea with proportional quantity and the
long chain acid with proportional quantity are dissolved in a
pyridine solvent with
nitrogen protection, reflowed at the temperature of 140 to 220 DEG C by adopting a temperature
programming method, and react for 3 to 4 hours, then the mixture is cooled to the
room temperature and recrystallizated by using the
ethanol of 95 percent to obtain the brown product.