In recent years, with the rapid development of electric vehicles (EVs), the connection of a large number of EVs to the power grid has adversely affected the economic operation and system stability of the power grid. Therefore, research on the effective dispatch of EVs is of great significance. This paper proposes a day-ahead scheduling strategy for EVs based on converted economical objective, which makes full use of the flexibility of EV loads, takes into account the interests of the grid side and the user side, and reduces the negative impact of EVs connected to the grid. For the limitation of the objective function with the smallest variance, objective function converts the technical index of grid load peak-to-valley difference into an economic index with the smallest charging cost for users, and uses CPLEX to solve the day-ahead scheduling model of small-scale fast charging stations. The calculation example shows that this strategy can effectively reduce the peak-to-valley difference of grid load, which proves the rationality of the strategy.