Abstract: In this paper, the ANSYS software based on the finite element method was introduced to calculate the distribution of electric field intensity in multi-wire ionization chamber with different models and voltages. Furthermore, the influences induced by the radius size of wire, distance between anode and cathode, distance between wires, and voltage on ionization chamber electric field were also specified. The results indicate that the fluctuation of electric field intensity in the ionization chamber can decrease by decreasing the radius size of wire, distance between wires and voltage and increasing distance between anode and cathode, which is helpful to obtain stable electric field.