The condensation effect of the overhead condenser in propylene rectification tower gradually decreased after the first start-up, resulting in the overpressure of the tower and the serious waste of propylene in the bottom of the tower, which brought great economic losses and potential safety risks to the plant. In order to solve this problem, the insufficient water supply of circulating water station and the biological fouling were ruled out one by one by analyzing the fouling of heat exchange equipment and taking a series of measures. It was judged that the main reason is the particulate fouling in circulating water of condenser, and a scheme was formulated to switch out the condensers one by one for hydraulic cleaning. Finally, the heat exchange efficiency was restored, the production bottleneck was eliminated, and the production demand was met. At the same time, the causes of particulate fouling in condenser were analyzed and relevant optimization measures were taken for the propylene rectification tower, so as to delay the fouling and impurity blockage and make preparations for the subsequent cleaning.