Aiming at the problem of unclear understanding for heavy oil flow during lifting in wellbore, heavy oil with high viscosity (584.24 cp, 1.889 g/cm3) was used in this paper to study the flow characteristics of heavy oil-water in upward pipe. All the flow patterns identified can be grouped into five flow categories. Unlike low-density oil-water flow, phase inversion did not occur in this study which is in agreement with a surface energy equation. Slippage effect which was evaluated by water holdup measurements tends to be more significant with decreasing mixture velocity or increasing input water fraction. The flow pattern-based modified drift-flux models and momentum equations proposed in the current study perform well on water holdup prediction, the error rate is less than 20%. Lastly, the total pressure gradient was found to be gravity dominant at low water holdup while be friction dominant at high mixture velocity or high-water holdup. The pressure gradient prediction model of heavy oil-water central annular flow based on Bannwart model is established, and the error rate is less than 30%. This paper provides a theoretical basis for further improving the prediction accuracy of flow parameters during heavy oil lifting in wellbore.