UV photo-curing methods, which offer an alternative to conventional thermal curing, are widely employed in trenchless rehabilitation of sewage pipelines. However, enhancing construction safety and quality requires the optimization of GRP-CIPP thickness, reduction of VOC emissions during the UV photo-curing process, and development of fire prevention technologies owing to potential fire hazards during construction. In this study, a low-level VOC-CIPP (LV-CIPP) incorporating internal and external gas-blocking films was utilized to significantly reduce the concentration of styrene emissions generated during the UV photo-curing process. Additionally, a non-combustible air conversion system was developed and implemented to mitigate fire risks during the construction process. Fire risk can be substantially reduced by maintaining the oxygen concentration of the CIPP inflow air below the threshold defined by oxygen dilution extinguishing conditions.