The invention provides an industrial preparation method of palonosetron hydrochloride. The method comprises the following steps: firstly carrying out a reaction on the raw material [1-azabicyclo(2.2.2)octyl-3s-yl]-(1,2,3,4-tetralin-1s-methyl)amine and triphosgene and boron trifluoride diethyl etherate, then adding dilute acid and a stabilizing agent for reflux and obtaining palonosetron hydrochloride free base through extraction; and salifying the palonosetron hydrochloride free base with concentrated hydrochloric acid in mixed solvents including C1-C3 alkyl alcohols and acetone, thus obtaining palonosetron hydrochloride. By the method, the defects of column purification, complex aftertreatment and multiple refining in the prior art are overcome. The method has the following beneficial effects: the method is simple and convenient to operate; the production period is short; and the purity of the obtained product is more than 99.5% and the individual impurity is below 0.1%.