One-dimensional thunderstorm electrification model was used to simulate the basic electrific characteristics of a thunderstorm case in STEPS. The simulated charge sturcture is the classic dipolar structure:positive charge in the upper part of thunderstorm while negative in the lower part; the evolution law of electrical field in discharge layer becomes sawtooth; the vertical distribution of the positive and negative electrical field locations conforms to the typical electrical field distribution of thuderstorm.Furthermore, a sensitivity test is carried out to analyze the impact of cloud base height and temperature lapse rate on electrical process of thunderstorm. Results show that when the cloud base height decreases, the discharging location goes up and lightning becomes frequent, the first lightning appears sooner. The first lightning has to defer but lightning frequency decreases with the temperature lapse rate increasing, respectively.