Lithium metal has been considered as one of the most promising anodes for rechargeable battery due to its high theoretical capacity. However, lithium metal has never satisfied the demand of rechargeable battery with respect to cycle life and safety issues on account of electrolyte decomposition and dendrite formation on lithium surface during electrochemical cycling. Here, we propose a novel electrolyte system that is relatively stable on lithium metal and alleviating the dendrite growth rate. Systematical design methods have been employed combining simulations, model experiments, and in situ analyses. The reduction potential of solvent, anion size of salt and viscosity of electrolyte are found to be crucial parameters. The lithium metal anode in contact with a designed electrolyte shows a remarkable cyclability more than 100 cycles at a high areal capacity of 12 mAh cm-2.