<p>Utilization of waste plastics (WPs) as energy and/or chemical sources is an important coal-based routes substitute for hydrocarbons recycling. Pyrolysis of WPs is a promising valorization strategy but suffers from the complexity of products. Herein, we proposed a new process for the pyrolysis of WPs into alkenes in the molten salt (Li₂CO₃-Na₂CO₃-K₂CO₃) environment. The pyrolysis performance was investigated by using disposable waste mask (DWM) as typical WPs in molten salt reactor. Alkenes (C₂H₄ and C₃H₆), methane, CO and H₂ are the main products at 700 °C following with an alkene yield of 52.5 wt%. The molten salt acts as heat carrier, reaction medium and pyrolysis catalyst, which enables the fully conversion of disposable waste mask (DWM) into light alkenes and synthesis gas rather than tar or char. The feeding of CO₂ promotes the polyolefins reforming via the reduction of CO₂ into CO and depresses the weak decomposition of carbonates in the molten salts. This study provides a novel process for the efficient conversion of WPs into alkenes, which will be driven by concentrated solar power or waste heat.</p> Graphical Abstract <p></p>