If the voltage stability of distribution network is analyzed according to power flow calculation method, inverter based distributed generation could get into the current limiting status after distribution network voltage drops to a certain degree due to its inverter’s current limiting function. So a novel Iθ bus model is introduced to describe the inverter based distributed generation under current limiting status. Meanwhile a power flow calculation method based on the Iθ bus type is proposed. According to the variation of bus power equation of Iθ bus and the Newton iteration method, a new Jacobian matrix and correction equations are established to calculate the power flow. Finally, some tests are done in a typical IEEE33 distribution network to verify the proposed method. The results show the method is correct and accurate. This work is supported by National Natural Science Foundation of China (No. 51507139), the Key Discipline Special Foundation of Shaanxi Province (No. 5X1301), and the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 20126118110009).