The invention relates to a chemical reaction separation device and method, in particular to a septal catalysis rectifying tower for low-level carboxylic ester hydrolysis and an application of the rectifying tower. The rectifying tower comprises a condenser and a reboiler, a horizontal partition plate is arranged in the rectifying tower, so that the rectifying tower is divided into a reaction areaand a public stripping section by the horizontal partition plate, a vertical partition plate is arranged in the reaction area, so that the reaction area is divided into a reaction side and a recyclingside by the vertical partition plate, a gas phase redistributor is arranged below the horizontal partition plate and comprises down-comers and gas channels, the down-comers are arranged on two sidesof the rectifying tower, and the gas channels are formed in the horizontal partition plate, positioned on two sides of the vertical partition plate and provided with valves. By the aid of the device,the hydrolytic conversion rate of carboxylic ester can reach 99.99%, alcohol products with the purity larger than 99%, production processes are greatly simplified, and device size, energy consumptionand operation expense are reduced.