This paper introduces working principle and technical features of vacuum filter in emulsion system for tandem cold strip mill.Based on specific cases,this paper analyses and assesses the effect before and after using the emulsion system with the usage of the vacuum filter for strip mill.Compare with the effect when using the first generation vacuum filter,the emulsion quality is improved significantly by using the second generation vacuum filter,which at the same time ensures steady operation of the rolling mill and surface quality of the mill products. As a result,investment and running costs are lowered,emissions of the waste emulsion are reduced,waste water treatment costs are reduced and so as the environmental pollution.It can be seen the second generation vacuum filter has obvious economic and environmental benefits.Therefor,it suggests that the filter should be used widely in the field of automotive,environmental protection rolling steel and nonferrous metals. This paper introduces working principle and technical features of vacuum filter in emulsion system for tandem cold strip mill. Based on this paper analyzes and assesses the effect before and after using the emulsion system with the usage of the vacuum filter for strip mill. Compare with the effect when using the first generation vacuum filter, the emulsion quality is improved significantly by using the second generation vacuum filter, the emulsion quality is improved significantly by using the investment and running costs are lowered, emissions of the waste emulsion are reduced, emissions water treatment costs are reduced and so as the environmental pollution. It can be seen the second generation vacuum filter has obvious economic and environmental benefits.Therefor, it suggests that the filter should be used widely in the field of automotive, environmental protection rolling steel and nonferrous metals.