Herein, we report the in situ synthesis of dual-component poly(AM-co-NVP) and poly(HEA-co-NVP) polymers (AM = acrylamide, HEA = 2-hydroxyethyl acrylate, NVP = 1-vinyl-2-pyrrolidone) based on two incompatible phases via laser-ignited inhomogeneous biphase frontal polymerization (FP) within 10 min. Once initiated, the monomers converted to polymers spontaneously without the need for any external energy owing to the traits of exothermic polymerization, providing a facile, rapid and cost-effective approach. The dependence of the frontal velocities and temperatures on initiator concentration and the monomer weight ratio was systematically investigated. Moreover, an operable bilayer film with two fluorescent signals was obtained by simply introducing fluorescent carbon dots (CDs) and quantum dots (QDs). The as-prepared fluorescent bilayer film realized white light emission and could be conveniently applied onto a commercial UV light-emitting diode (LED) to generate white LEDs. We believe the methodology developed in this work may promote the development of various inhomogeneous multicomponent polymers and LED nanocomposites in a fast and efficient way.