||The extension of absorption from broad range of light is substantially considered to improve photocatalysis. Herein, novel organocarbosilane based polymer nanocomposites containing organic dye (Coumarin153) and upconversion nanoparticle (UCNP) are rationally designed and uniformly dispersed to achieve the extended absorption range through dual energy conversion. In the well-organized nanocomposites, Coumarin153 absorbs UV-Visible light (390~490 nm) to down-convert to 500~580 nm whereas yellow-emission UCNP absorbs NIR light (980 nm) to up-convert to the emission of 500~580 nm, also, corresponding to absorption range of Rose Bengal (RB). Moreover, the polymer nanocomposite resin with optical transmittance in 480~600 nm is coated to the inner channel surface of PDMS microfluidic device. As a result, the fabricated nanocomposite-microfluidic chip on PDMS shows more than 20% higher photocatalysis under white LED and IR laser, than the only RB used at azs-Henry reaction.