This paper describes the development of a new three-component polymerization route to functional poly(tetraarylethene)s (PTAEs). The polycoupling reactions of internal diynes, aryl diiodides, and arylboronic acids proceed smoothly in the presence of PdCl2 and NaF at 70 degrees C in dimethylformamide, generating PTAEs with promising molecular weights in high yields from different monomers. Most of the PTAEs are soluble in common organic solvents and are thermally stable. Some of the PTAEs exhibit the phenomenon of aggregation-induced emission: their light emission in solution is enhanced by aggregate formation. The tetraphenylethene-containing PTAE can function as a fluorescent chemosensor for detecting Ru3+ ions with high sensitivity and specificity. It is also a promising material for the fabrication of fluorescent pattern by photolithography process. All the PTAEs possess good film-forming ability and their thin films exhibit high refractive index (RI = 1.7751-1.6382) at 632.8 nm, whose values are higher than those of commercial polymers such as polycarbonate and polystyrene.