Here, we investigated photochromic glass fibre threads produced with the sol-gel coating technique and used it as sewing threads to produce stitched glass-polypropylene composites. The possibility of making sol-gel photochromic glass fibre threads, the morphology of the glass fibre thread and the tensile property of glass fibre sewing threads before and after sol-gel treatment have been studied in this work. The photochromic glass fibre thread was successfully stitched into glass-polypropylene composites as sewing threads and showed an efficient and effective response to UV light. Our results indicate that sol-gel coating is an efficient way to produce photochromic glass fibre. In addition, the sol-gel coating does not significantly affect the tensile performance of the glass fibre.