Abstract: The aim of the study was to improve a measuring apparatus,which could be used to examine the concentration of negative ions for textiles,so that it is logical to use the apparatus.By analyzing the characteristic of negative ions generated by textiles and the operation principle of the apparatus,and combining with performing an experiment on electrostatic distribution,the problem of electrostatic interference generated in textile negative-ion measurement was presented.With the proper metallic shield,electrostatic interference was eliminated,and the effect of shielding was demonstrated by experiments.It is logical to use the improved apparatus to measure the property of negative ions for textiles.