Abstract: Analyse the structure and working principle of XMZ-750 pressure filter.There were lots of problems such as long filtration time,low dehydration efficiency,high failure rate and maintenance cost.The KMZG450 /2000-U type efficient quick-open pressure filter has the advantages of advanced design,high degree of automation,convenient operation,so Tunlan coal preparation plant replaces the XMZ-750 pressure filter with four sets of KMZG450 /2000-U ones and auxiliary equipment.After transformation,eliminate the potential safety hazard caused by primary filter girder crack,reduce six sets of equipments and four workers.The pressing efficiency is improved by more than four times,the moisture content of filter cake is reduced to less than 18 percent,the level of automation is improved,the coal slime recovery system is optimized,the mass fraction of circulating water is decreased from 13 g / L to less than 9 g / L.Improve the separation efficiency of heavy medium system,the clean coal yield is increased by 0.5 percent,medium consumption is reduced by 8 percent,the profits increase by 2.535×107 yuan every year.Provide the improvement methods for KMZG450 /2000-U type efficient quick-open pressure filter from the aspects of operation and maintenance,the connection between posts and pipe design optimization.Perfect the properties of new type pressure filter by installing liquid level sentor in filtrate receiver and aerated water separator at end,connecting the barrel bottom,reducing the length and elbows of air blowing pipe,installing dual pull type movable cover.