The dyeing of nylon 66 fabric was carried out using three dyes,namely ERIOFAST red 2B,yellow 5G,and blue 3R.The effects of dyeing solution pH,dyeing promoter types and dosage on the color yield were studied,and the dyeing curve and lifting force curve were analyzed.The optimized dyeing process of nylon 66 with ERIOFAST reactive dye was as follows:dyeing solution pH 4.5~5.0,calcium chloride 10%(omf),step heating to 98℃for 40 min.The dyed nylon 66 fabric under the optimal process had excellent color fastness to friction,sweat,soap,and water washing.Furthermore,all three ERIOFAST dyes exhibited high dyeing enhancement power.