The macroseismic intensity is a subjective indicator of ground motion intensity. Convex analysis method and China Probabilistic Seismic Hazard Analysis methodology are combined to derive peak acceleration for Ningbo city, China. The peak acceleration interval obtained by using the convex set theory-based seismic hazard analysis methodology is compared with that calculated by using China Probabilistic Seismic Hazard Analysis methodology. The sensitivity analysis indicates that the interval of peak acceleration is most sensitive to the annual occurrence rate. Furthermore, the correlation of uncertain variables cannot be neglected for peak acceleration prediction.