The invention provides a locating and sizing method of a static synchronous series compensator. The method comprises the steps of: constructing a target function for locating and sizing of the static synchronous series compensator, and determining the constraint conditions of locating and sizing; and adopting a catastrophic variable speed quantum genetic algorithm to calculate the function value of the target function, comparing the target function values of individuals in a group, and further determining the optimal installation position of the static synchronous series compensator and an injection voltage amplitude. Compared with the prior art, the locating and sizing method of the static synchronous series compensator starts from a plurality of targets, the optimal line and capacity are searched in the total network lines for the installation of the static synchronous series compensator, and the comprehensive level of the economic performance and the stability of the power grid is improved.