The invention relates to a cooling agent and a synthesis method thereof. The synthesis method of the cooling agent comprises the following steps of 1, cleaning up a reactor by an 
ethanol solution, and removing air in the reactor, 2, adding an 
ethanol solution as a reaction 
solvent, 
umbelliferone and a Pd / C catalyst into the reactor, feeding 
hydrogen into the reactor, and heating for a reaction lasting for 6 to 8 hours, and 3, removing the Pd / C catalyst, adding NaBH4 into the product obtained by the step 2 for a sequential reaction, acidizing the reacted mixture obtained by the sequential reaction, carrying out extraction by 
ether to obtain extract, and carrying out reduced pressure 
distillation of the extract to obtain the cooling agent, wherein the cooling agent comprises four 1-
isopropyl-4-methylbicyclo[3.1.0]-hexyl-2-
alcohol structural isomers. The cooling agent has a gentle cool taste, long time of duration, obviously low 
irritation on the laryngeal, an obviously slight dry 
sensation, and a very strong moistening feel.