The China-Pakistan Economic Corridor (CPEC) has experienced increasing rainstorm flood risk, posing significant threats to infrastructure and socio-economic development under global environmental change. Evaluating flood risk along the corridor is crucial for informing disaster prevention, mitigation, and adaptive planning. This study develops a comprehensive flood risk assessment model based on the Hazard, Sensitivity, Vulnerability, and Coping capacity (HSVC) framework, integrating meteorological, geospatial, and socio-economic data from 1979 to 2024. The AHP-Entropy method was applied to determine the relative importance of factors, including extreme rainfall, natural conditions, population, and infrastructure. High-risk areas were identified primarily in the central plains and southern lowlands, forming continuous bands, whereas low- and mid-low-risk zones were concentrated in northern mountainous and transitional regions. Comparing 1979-1999 (P1) with 2000-2024 (P2), low- and mid-low-risk areas remained largely stable, while middle- to high-risk zones expanded significantly, indicating a gradual increase in overall flood risk. Extreme rainfall emerged as the dominant driver, exerting the strongest influence on flood intensity and spatial distribution, while sensitivity, vulnerability, and coping capacity further shaped the heterogeneous risk pattern. Model simulations showed high agreement with historical flood records, validating the approach. These findings provide a scientific basis for targeted flood management, infrastructure reinforcement, and resilience enhancement along the CPEC corridor.