The method provides a device for separating gamma-terpinene and paracymene with a eucalyptus oil climbing-film fractionating tower, belonging to a fractionating tower for producing eucalyptus essential oil. A condensing reflux channel with a heat exchange area of between 50 and 70 percent is arranged between a fractional condenser of a common fractionating tower and the top of the fractionating tower, that is, heat exchanging tube bundles which are accordant with the air flow direction of the tower are evenly arranged on a tube plate pan, and the tube laying area of the tube bundles is 35 percent of the pan area. The device maintains the prior process condition, reduces volatilization capacity of the gamma-terpinene and the paracymene, enlarges the relative volatility of each composition in eucalyptus crude oil, ensures that the content for one-time fractionating eudesmin reaches over 80 percent, increases the degree of separation, reduces the cost, avoids material consumption caused by newly added equipment, and in particular receives excellent effect in production.