In order to study the influence of ice crystal multiplication on non inductive electrification during the development of thunderstorm, a three dimensional numerical model of thunderstorm was used to evaluate the distribution of the variant particles, charge and the electric field in the thunderstorm with an ideal environment. The result shows that there is an ice crystal gathering area in the lower part of the thunderstorm with ice crystal multiplication during its development and mature stage. It makes the number of ice crystals in the case of multiplication increase by 15%-18% and the gathering area become larger compared to the condition without multiplication. And multiplication also makes the number of graupel particles in the condition with multiplication increase about 20%. The positive charged region always occurs nearby the area with high graupel concentration, while the negative charged region always appears in the overlap region with the high ice and graupel concentrations. Multiplication firstly influences the ice and graupel concentration and spacial distribution, then makes the non inductive electrification in thunderstorm more powerful and location change, and even the electrification process in single cell storm starts ahead 5-6 min.