To solve the problem of mismatch between the construction of a grid and the popularity of electric vehicles (EVs), this paper conducts research on the assessment method and optimization strategies of charging load acceptance capacity of a distribution network. First, the charging load acceptance capacity of the distribution network is measured by the charging pile acceptance capacity, and the factors influencing that capacity of the distribution network are analyzed from the distribution network, charging pile and user sides. Secondly, a charging load assessment model based on the number of charging piles is established. The charging load is calculated based on the number of charging piles and vehicle-to-pile ratio, and then the coupling relationship between charging load and distribution network is used to analyze the operational risk of the distribution network. Furthermore, a comprehensive operational risk of the distribution network is established by taking into account the voltage and current crossing risk and the distribution transformer overload risk as a quantitative indicator of the charging pile acceptance capacity. This is proposed as a quantitative indicator of charging pile acceptance capacity. Then, from the grid side, strategies such as network reconstruction, distribution network expansion, and two feeders jointly supplying power are proposed to improve the charging pile acceptance capacity. Finally, through simulation analysis, the effectiveness of the charging pile acceptance capacity evaluation model and optimization strategy is verified. This work is supported by the National Natural Science Foundation of China (No. 51777077).