The invention provides a surface modification processing method of an alloy fiber, which comprises the following steps of: (1) putting an alloy fiber to be processed in degreasing fluid to be degreased; (2) immersing the alloy fiber which is subjected to the degreasing in the step (1) into chemical oxidant solution until the fiber is blue or black, wherein the temperature of the chemical oxidant solution is 50-90 DEG C; (3) immersing the alloy fiber which is oxidized in the step (2) into hardening fluid for 1-10min, wherein the temperature of the hardening fluid is 50-80 DEG C; (4) immersing the alloy fiber which is subjected to the hardening in the step (3) into confining fluid for 1-10min, wherein the temperature of the confining fluid is 60-100 DEG C; and (5) cleaning the alloy fiber which is subjected to the confining in the step (4) by clean water, and drying. According to the surface modification processing method disclosed by the invention, the corrosion resistance of the alloyfiber can be improved, simultaneously, the surface tensile and the polar component of the alloy fiber are improved, and further, the surface hydrophily of the alloy fiber can be improved.