The concept of combination synchronization is introduced into complex network, for investigating finite-time combination synchronization of four uncertain complex networks. Four complex networks, which are effected by unknown parameters and uncertain disturbances at the same time, are combined as the form of A$+B+$C-D. Based on the sliding mode control principle and finite time stability theory, the sufficient conditions of synchronization are obtained with designing appropriate network sliding mode surface and control inputs. Finally, a numerical example is given to illustrate the effectiveness of the proposed scheme.