Tropical cyclones are often accompanied by heavy rainfall, high tides, and strong wind speeds, which can induce serious compound floods resulting in immeasurable losses to coastal areas. Studies on flood risk for ocean engineering by compound impacts of rain, tide, and wind are still limited to date. The west artificial island of Hong Kong-Zhuhai-Macao Bridge is a vital link between the immersed tunnel and the bridge. The flooding on the artificial island under the compound effects of rain-tide-wind and the flood risk of cars were analyzed in this study. We propose rain-tide-wind joint probabilities for different compound scenarios based on historical observational data of tropical cyclones. The artificial island hydrodynamic model was created to evaluate flood disasters induced by rainfall and wave overtopping. The 24-hour flood process and maximum flood depth distribution of each scenario are presented. The car damage in floods by the compound effects was assessed to derive the probability-car damage curve for risk assessment. The study provides technical support for artificial island flood prevention and disaster risk reduction.