Flexible integration and consumption of renewable energy in DC distribution network has good application prospects. The ability of renewable energy consumption of DC distribution system and the quantitative evaluation method of the constraints are studied, and it is proposed that the impedance of DC network, the short circuit capacity of AC grid and the capacity of converter are three key factors affecting the ability of renewable energy consumption. Based on a typical DC distribution system structure, the impact of factors at DC and AC sides limiting the ability of renewable energy in DC distribution network are calculated. A practical algorithm for quantifying the ability of renewable energy consumption in DC distribution network is given. Results of calculation on a typical DC distribution system verify the correctness of the factors. Conclusion of this paper can provide a design and operation reference for renewable energy capacity configuration in DC distribution system.