▎ 摘　　要

NOVELTY - Preparing humidity response color-changing fiber comprises (i) preparing nano-microspheres, (ii) dissolving the hydrophilic polymer and background material in a solvent to obtain a spinning precursor solution of a preset concentration, (iii) adding the nano-microspheres to the salt solution and alcohol solution according to the preset mass ratio to form a coagulation bath uniformly dispersed with the nano-microspheres, (iv) extruding the spinning precursor liquid through the spinneret of the spinning machine to form a stock solution that flows finely into the coagulation bath, attaching the nano-microspheres to the surface and inside of the fiber. The the moisture-swellable fiber comprises but not limited to polyvinyl alcohol, sodium alginate or chitin fiber. The alcohol solution is one phase or many phase mixed solution of ethanol, methanol and isopropyl alcohol. The salt solution comprises but is not limited to a sodium sulfate solution or a calcium chloride solution. USE - The humidity response color-changing fiber is useful in fabric weaving and realizing the visual monitoring of environmental humidity (claimed). ADVANTAGE - The fiber: is capable of developing color when meets water and has fast response and simple preparation process.