In order to investigate the fluid dynamics and heat transfer characteristics of annular inner ribbed convex cells with ellipsoid inserts and enhance their comprehensive heat exchange efficiency, the fluid flow and heat exchange characteristics of smooth tubes and annular inner ribbed convex cells with ellipsoid inserts were compared by numerical simulation techniques. Through this analysis, the advantages of ellipsoidal plug-in in annular inner ribbed convex cell were verified in heat exchange, and the effects of three plug-in structural parameters, such as long-axial ratio, inclination angle and pitch on thermal performance of annular inner ribbed convex cell were further discussed. The results show that the heat exchange efficiency is significantly improved due to the synergistic effect between the plug-in and the convex cell after the plug-in is introduced into the annular inner rib convex cell. The performance evaluation criterion (PEC) can be increased by 13.62% as compared with the annular inner ribcage without plug-in. Under the condition of keeping the angle and pitch unchanged, the maximum PEC value can reach 1.34 when the ratio of long axis to long axis is 9∶5. Under the condition of fixed pitch and long axis ratio, the comprehensive heat transfer performance of the tube is the best when the inclination is 30 degrees. When the pitch is 20 mm, the maximum increase of PEC compared to the annular inner ribered convex tube can reach 20.30% under the condition of keeping the inclination angle and the ratio of long and short axis unchanged.