Dual functional mesoporous silica (mSiO2) colloidal electrolytes are promising to protect lithium anode and accelerate the reaction kinetics on cathode for lithium oxygen batteries (LOBs). In this work, we achieved a significantly extended battery life (from 55 to 328 cycles) of LOB by using mSiO2 with a concentration of 80 mg L-1 in the colloidal electrolyte, compared with the one using conventional LiClO4/DMSO electrolyte. The rate performance and full-discharge capacity are also dramatically enhanced. The as-synthesized mSiO2 has a special ordered hexagonal mesoporous structure, with a high specific surface area of 1016.30 m2 g-1, which can form a stable colloid after mixing with 1.0 M LiClO4/DMSO. The side reactions of Li stripping/plating are suppressed, thus the cycling life performance of LOB is enhanced by relieving the attack of superoxide intermediates. The co-deposition of mesoporous mSiO2 and Li2O2 also effectively accelerated the decomposition of the discharge product by promoting the mass transfer at the cathode. This investigation of suppressing side reactions using non-aqueous electrolytes will shed a new light on the design and development of novel lithium metal batteries.