Vane pump has been a very popular power source and its noise also has been a great disaster for hydraulic systems. The working principle of doubleacting vane pump was introduced, the principle and arrangement of the pump station of OL1600S highpressure casting machine were described,the noise problem of the vane pumps was analyzed.By analyzing,three problems of the hydraulic system were discovered,namely hydraulic oil contamination, hydraulic oil deterioration and cavitation erosion of the vane pumps.The system was improved by taking the following strategies: changing all the filter cartridges, replacing all the hydraulic oil and cleaning the oil tank, placing filter nets between the oil returning zone and oil suction zone, using 500 μm filter cartridges in the suction filter instead of 50 μm filter cartridges. Those strategies work very well and the vane pumps have run smoothly by now.