Dual-site magnesium doping is successfully utilized to enhance the electrochemical performance of Li2MnSiO4/C/rGO. Both Li-site and Mn-site Mg doping decline the particle sizes and stretch Li-O bond, resulting in the improved Li+ diffusivity by over one order of magnitude. The Li-site Mg doping increases the carrier mobility and reduces the band gap of Li2MnSiO4, leading to the improved electronic conductivity. Additionally, the Mn-site Mg doping eases the volume change of Li2MnSiO4 during Li+ extraction and insertion, which contributes to the enhanced structural stability. Consequently, Li1.98Mg0.02Mn0.94Mg0.06SiO4/C/rGO composite delivers a high initial discharge capacity of 258.0 mA h g(-1) and retain 206.7 mA h g(-1) after 50 cycles at C/16 rate between 1.5 V and 4.7 V. More importantly, its discharge capacity is increased by 25.9% to 178.4 mA h g(-1) at C/2 rate, compared with Li2MnSiO4/C/rGO composite. Besides, its capacity retention is as high as 90.3% after 100 cycles.