Flame retardant working solution and flame retardant finishing method for pure cotton fabrics and/or cotton-polyester blend fabrics

Provided are a flame retardant working solution and flame retardant finishing method for pure cotton fabrics and/or cotton-polyester blend fabrics employing the flame retardant working solution. The flame retardant working solution comprises the following components: a flame retardant, a crosslinking agent, and the balance being water; the flame retardant in the flame retardant working solution has the concentration of 200-600 g/L, and the crosslinking agent has the concentration of 30-100 g/L. Cotton-polyester fabrics or pure cotton fabrics obtained by employing the flame retardant working solution and finishing method has good flame retardant effect and good washing resistance; the cotton-polyester fabrics pass through the GB/T 5455-1997 test, with the afterflaming time and smoldering time of less than 5 seconds after being washed thirty times, and a damaged length of less than 15 centimeters, reaching level B1 according to the GB/T 17591-2006 "flame retarded fabrics" standards, and can be widely used in flame retardant finishing of clothing, tents, upholstery fabrics and fabrics for transportation vehicles.