The invention provides an energy storage demand evaluation method and system, a terminal and a readable storage medium. The method includes: acquiring capacity of current energy storage connected intoa power supply side of a power system and a current evaluation index under the current energy storage capacity; judging whether the current evaluation index is greater than or equal to a preset evaluation index; and determining the current energy storage capacity as final energy storage capacity of energy storage demand evaluation when the current evaluation index is greater than or equal to thepreset evaluation index. According to the method, for different new-energy power generation consumption targets in the power system, demand capacity which is of energy storage equipment of the power supply side and corresponds thereto is obtained on the basis of work and running characteristics of an energy storage system in the power system, energy storage demand situations of the power supply side of the power system in a case of meeting the new-energy consumption targets can be reflected, and precision of the energy storage demand evaluation method is improved.