Plug-in hybrid electric vehicles (PHEVs), including extended-range electric vehicles (EREVs), strike a balance between performance and efficiency. They help alleviate consumer concerns over driving range during long-distance travel and address energy replenishment challenges in areas with limited charging infrastructure. As such, PHEVs represent a key technological pathway for achieving rapid energy conservation and emissions reduction in the automotive industry’s transition toward green energy. This chapter focuses on PHEVs as the primary subject of study. It analyzes national and local-level industrial policies and market developments, examines vehicle operation data and the operational characteristics of PHEVs in representative cities, and identifies patterns in vehicle usage and user behavior. The goal is to support the technological advancement and healthy development of PHEV products.