The hybrid magnesium-lithium ion batteries (MLIBs) have drawn much attentions in recent years, which make full use of high safety of magnesium anode and high mobility of lithium ions cathode. However, the development of high energy density MLIBs is hindered due to the limitation of suitable cathode materials. In this work, the MLIB based on LiV3O8@GO cathode is reported for the first time. Moreover, the LiV3O8@GO delivers a remarkable discharge capacity of 245.9 mAh g−1 (at 50 mA g−1), a rate performance of 186.6 mAh g−1 at 500 mA g−1 and high cyclic stability (71% of initial capacity remained after 500 cycles). With an average voltage around 1.75 V and a high discharge capacity of 245.9 mAh g−1, the high energy density about 430.3 Wh kg−1 is obtained, which will play a great role in promoting the practical application of MLIBs. Furthermore, we investigated the electrochemical mechanism with complex phase transition. The excellent electrochemical performance proves that LiV3O8@GO is a potential cathode material for the high energy density MLIBs.