To deal with the problem of the increasing operating loss of a distribution network caused by the disorderly large-scale charging of electric vehicles (EVs), a charging optimization strategy guided by the dynamic tariff mechanism of a subregion is proposed. The dynamic electricity price mechanism is to establish different dynamic electricity prices according to the load characteristics in different regions to optimize EV charging in the corresponding regions. The dynamic electricity price model taking into account the total charging power of the charging station is established in the commercial area, and the dynamic electricity price model taking into account wind and photovoltaic power output is adopted in residential and office areas. A charging benefit coefficient model is proposed to improve the charging time satisfaction of users in residential and office areas. Finally, the simulation results on the IEEE33-node system show that the EV charging optimization strategy proposed can not only guarantee the interests of the car owners, but also reduce network loss, improve the voltage quality of the distribution network, promote wind and photovoltaic power consumption, and enhance the economy of the distribution network.