The dynamo-type flux pump is a non-contact superconducting magnet excitation device based on the principle of electromagnetic induction, with its output characteristics significantly influenced by the number of rotor permanent magnets and the system structure. Our previous research indicates that as the number of rotor permanent magnets increases, the output voltage of the flux pump initially rises and then decreases, revealing the impact of magnetic field strength and distribution on the output performance. To further investigate this phenomenon, this study conducted simulations to analyze the effect of adding an iron yoke on the superconducting stator side on the DC output characteristics of the flux pump, and examined how changes in the number of rotor permanent magnets affect the system. Given the introduction of ferromagnetic materials, the H-A method was employed for modeling and simulation. The results show that adding an iron yoke significantly improves the DC output voltage of the flux pump. However, as the number of permanent magnets continues to increase, the magnetic field interference between adjacent magnets intensifies, causing the enhancement effect of the iron yoke on the output voltage to first increase and then weaken. Through an in-depth analysis of the magnetic field distribution, electric field distribution, and current density, this study reveals the mechanism by which the iron yoke influences the DC output voltage of the flux pump, providing theoretical support for further optimizing the performance of dynamo-type flux pumps.