The invention provides a substation dynamic reactive power optimization method and a system based on an improved bat algorithm. A substation dynamic reactive power optimization mathematical model is built, the substation dynamic reactive power optimization mathematical model is solved by employing the improved bat algorithm, and the optical action strategy of a substation tap and a capacitor set is obtained. In the whole process, the bat algorithm is applied to the field of dynamic reactive power optimization, the bat algorithm is improved by employing a heuristic strategy aiming to security constraint and control equipment action constraint, the condition of local optimum of the algorithm is effectively avoided, optimal control of reactive power of the substation voltage can be realized, and normal and high-efficiency operation of the substation is guaranteed.