The problem of robustness-supported user association and small cell station ( SCS ) switching ON/OFF strategies in 5G millimeter wave ( mm-wave) networks is investigated, where the robust-ness of access links is ensured and the number of active SCSs is minimized for the reduction of the aggregation power consumption. Firstly, the problem is formulated as an integer programming ( IP) problem. Then the problem is proved as a NP-hard problem by means of the simplification into the minimum dominant set( MDS) , which is a NP-hard problem and is intractable to be solved in poly-nomial time. Secondly, a greedy-idea-based heuristic algorithm ( GIHA) is proposed under the con-sideration of the complexity of the original optimization problem. Finally, superiorities of GIHA are demonstrated with the extensive simulations in 60 GHz mm-wave ultra-dense network in terms of ac-cess robustness and aggregate power consumption.