The invention provides an optical composite layer structure with a built-in touch sensitive polymer dispersed liquid crystal (PDLC) structure. The optical composite layer structure comprises an upper transparent substrate, a lower transparent substrate, an upper transparent conductive layer, a lower transparent conductive layer and a PDLC layer. A PDLC circuit and a touch sensitive circuit are provided on the upper and lower transparent conductive layers. A cable region that is electrically connected to external soft circuit cables is provided at an end of the upper transparent conductive layer and the lower transparent conductive layer to electrically connect to an external control unit. With a touch sensitive operation of a touch sensitive circuit of the optical composite layer structure, a signal instruction is provided to the control unit. The corresponding PDLC circuit may drive the corresponding regions of PDLC layer to conduct the change of light transmission of local region.