The development and research of cobalt-free color-changing silica gel are based on blue color-changing silica gel. It is produced by impregnating fine-pore silica gel with an inorganic salt mixture to create orange color-changing silica gel. It uses a new non-toxic composite dye, fundamentally eliminating the environmental pollution caused by dyes and color-changing agents. With its unique technological conditions and excellentadsorption performance, the product has become a new generation of environmentally friendly products.