Based on the least square method and grey relational degree theory, a model for predicting the ownership of electric vehicles is established. The state transition matrix is introduced into the traditional parking demand model to predict the actual parking distribution characteristics of electric vehicles. Based on the Monte Carlo method, this paper aims at electric private cars, electric buses and electric taxis. The charging requirements of electric business vehicles are simulated respectively, and their charging behaviors are simulated respectively. The daily curve of charging load is obtained by simulation. The results show that the peak-valley difference of daily curve of electric vehicle charging load is large, and the demand of electric bus charging load will take up a large proportion.