TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Method: The geraniol is dissolved in dichloromethane, adding dimethyl sulfide at - 20-10 degrees C, then adding N-chlorosuccinimide, filtering for removing succinimide after reaction, after washing and drying dichloromethane solution, concentrating to obtain geranyl chloride. After adding the N-chlorosuccinimide, the temperature is - 5-5 degrees C and stirring for 2 hours. Acetoacetate is dipped into mixed solution of potassium carbonate and acetone, adding acetone solution of geranyl chloride after stirring for half an hour, filtering and concentrating after reaction, adding water and sodium hydroxide aqueous solution, heating at 50-60 degrees C by water bath and decarboxylation to obtain geranyl acetone, distilling and purifying to obtain sterling geranyl acetone, where mol ratio of geranyl chloride to ethyl acetoacetate is 1-2:1. The acetylene passes into methyl tertiary butyl ether mixture of inorganic base, and temperature is controlled at 5-10 degrees C, dipping methyl tertiary extinguishing with diluted hydrochloric acid after reaction; extracting and concentrating methyl tertiary butyl ether to obtain (E)-3,7-11-trimethyl dodecane-6,10-diene-1-alkyne-3-alcohol, where inorganic base is potassium tertbutoxide, sodium tert-butoxide or sodium methoxide. Acetic anhydride and acid are added into (E)-3,7-11-trimethyl dodecane-6,10-diene-1-alkyne-3-alcohol, extracting and concentrating with methyl tertiary butyl ether to obtain (E)-3,7-11-trimethyl dodecyl-6,10-diene-1-alkyne-3-acetic ester, where acid is sulfuric acid, (poly)phosphoric acid or hydrochloric acid. Glycol dimethyl ether solution of (E)-3,7-11-trimethyl dodecyl-6,10-diene-1-alkyne-3-acetic ester is dipped into mixture of silver salt and glycol dimethyl ether, rearranging to obtain (E)-3,7-11-trimethyl-1,2,6,10-tetraalkenyl acetic ester, extracting and concentrating with methyl tertiary butyl ether after adding ice water, where silver salt is silver tetrafluoroborate, silver acetate or silver hexafluoroantimonate. Inorganic base aqueous solution is dipped into methanol solution of (E)-3,7-11-trimethyl-1,2,6,10-tetraalkenyl acetic ester, extracting with methyl tertiary butyl ether after adding ice water to obtain farnesal with 10% Z-type isomer, purifying to obtain E-type farnesal with sodium hydrogen sulfite salt-formation, where inorganic base is sodium carbonate or potassium carbonate. The reaction temperature during hydrolysis is 0-20 degrees C. Carbinol is added into mixture of farnesal, sodium borohydride and tetrahydrofuran; extinguishing with diluted hydrochloric acid after reaction; extracting with methyl tertiary butyl ether and distilling to obtain farnesol, where ratio of farnesal to sodium borohydride 1:1-1.2.