As traditional analysis is difficult to describe the complex nonlinear affiliation between voltage and reactive power accurately, the voltage offset caused by voltage control is ambiguous, leading to further deterioration of the voltage of some nodes in the system. Also, traditional voltage and reactive power analysis relies on the precision of model, however, there are still many problems in the establishment of load models, so it is necessary to study the correlation between voltage and reactive power by the voltage response data. This paper presents an identification of the relationship between voltage and reactive power in multi-scene based on Group-Lasso to mine the functional relation among load level of the system, reactive power and voltage. The method can quantify different impacts among the three precisely. The validity of the proposed method is verified by standard IEEE 24-bus system and IEEE 118-bus system. It provides a new way for the future analysis of connection between voltage and reactive power. This work is supported by National Natural Science Foundation of China (No. 51437003).