Hydrogen production from electrolytic water technology is an important way to solve the future energy crisis and realize green development. Among them, alkaline electrolytic water has simple structure and low cost, which is suitable for large-scale development. The concentration polarization caused by the bubble behavior in the alkaline electrolytic cell has a great impact on the performance of the electrolytic cell, reducing the contact area between the electrode and the electrolyte and increasing the resistance and the energy consumption of hydrogen production from electrolytic water. But most of the numerical simulation studies on electrolytic water do not consider the impact of the flow behavior of gas-phase products. In this work, the electrochemical model is coupled with the gas-liquid two-phase flow model, the drag force, lift force and bubble dispersion force are included in the equation describing the gas-phase volume force, and the influence of concentration polarization is considered. The gas production process of the forced circulation alkaline electrolytic cell is simulated, and the calculation results are more in line with the real flow state. The influence of operating conditions on the performance of the electrolytic cell is further studied. It is calculated that with the increase of electrolyte temperature from 60℃ to 80℃, the average current density increases by 3.84%, and the uniformity of current density distribution deteriorates. When the electrolyte flow rate is increased from 0.10 m/s to 0.30 m/s, the average current density and distribution uniformity can be improved simultaneously, and the average current density is increased by 0.64%. With the increase of potassium hydroxide concentration from 1 mol/L to 6 mol/L, the current density increases by 40.21%, but the uniformity of current density distribution deteriorates. And among the three operating variables, the electrolytic performance is the most sensitive to the concentration of potassium hydroxide in electrolyte. This work provides guidance for the internal mechanism research and operation parameter design of electrolytic water.