Abstract: There are high requirements to the time response of detector in profile gauge. For the high gas-pressurized ionization chamber detector, the electric field distribution in chamber is one of the important factors to determine its response time. The electric field distribution in the ionization chamber was simulated using the electric field simulation software ElecNet which was based on finite element analysis methods. Influence of the electric field distribution in ionization chamber on its output waveform signal was analyzed typically, the mechanism of trailing signal was also explained according to the simulation results. The research results provid guidance for the design and improvement of ionization chamber in profile gauge.