Abstract A robust searching hybrid differential evolution (RSHDE) method which can be used to solve the optimization problem of large-scale integer nonlinear systems is proposed. Two new schemes, the multi-direction search scheme and the search space reduction scheme, are embedded into the HDE. These two schemes are used to enhance the search ability before performing the initialization step of the solution process. Without these two schemes, the HDE is awkward in finding an efficient search direction in large-scale systems because of applying a random search method. In this study, the RSHDE is applied to solve the capacitor placement problem in distribution systems. Various-scales distribution systems are employed to demonstrate the application and verify the effectiveness of the proposed method. Moreover, the previous DE, HDE, simulated annealing (SA) and genetic algorithms (GA) methods are also applied to the same example systems for the purpose of comparison.