Traditional partitioning algorithms for reactive voltage are often using clustering algorithm of power flow calculation. These algorithms have some problems, such as complex computation and unable to reflect the network structure of power grid. To figure out those problems, a new algorithm for voltage control partitioning is proposed based on spectral clustering of complex network. First, the model of voltage control partitioning is established using the imaginary part of nodal admittance matrix; second, the algorithm adopts spectral clustering to analyze the model to get the low dimension clustering samples; then power system is partitioned by the improving K-means clustering algorithm. To ensure the credibility of partitioning result, evaluation system with three indexes is established to calibrate the partitioning result, such as modularity, reactive power balance and reactive power reserve, etc. To improve the accuracy of pilot nodes selection, the evaluation index of degree centrality is introduced. The simulation result of IEEE 39-bus testing system shows that the new algorithm is of effectiveness and superiority.