The polyester/cotton 50/50 blend fabrics were treated with 1,2,3,4-butanetetracarboxylic acid (BTCA) by pad-dry-cure process to improve the smooth drying property. Sodium acetate (SA), non-phosphorus compound, was used as an alternative catalyst, because the conventional catalyst, sodium hypophosphite (SHP), has disadvantages such as high cost, eutrophication, and shade changes in certain dyed fabrics. The reaction condition and mechanical properties of fabrics treated with BTCA/SHP or BTCA/SA were investigated. The ester-crosslinking reaction was influenced by curing temperatures, the concentration of BTCA and catalyst, and pH values of the padding liquor. The fabrics treated with BTCA/SA were comparable to those treated with BTCA/SHP in respect of wrinkle recovery, DP rating, and whiteness index, and had better strength retention. The content of carboxyl group in treated fabrics became higher with the increase of the concentration of BTCA.