Virtual backbones based on connected dominating sets(CDS) help to optimize multi-level hierarchical networks
from flat models in wireless sensor networks. However, the backbones are vulnerable due to frequent node/link failures.
Therefore effective approaches are needed to make the virtual backbones fault-tolerant and highly reliable. In this paper,
a distributed algorithm of 2-connected k-dominating set construction is proposed in unit disk graph network model. The
informations of every node and its neighborhood are used to construct k-dominating sets distributedly, and then k-dominating
sets are 2-connected. The complexity, approximation ratio and performance of the algorithm are given through theoretical
analysis. Experimental simulations show that the algorithm can produce less k-dominating nodes than traditional approaches.