The solid electrolyte interface (SEI) of Li metal batteries (LMBs) generated by traditional carbonate electrolytes is extremely unstable and prone to repeated rupture, resulting in a large amount of Li dendrites and dead Li, which seriously affects the cycling stability. In this work, we introduced trifluoromethanesulfonic acid trimethylsilyl ester (PMS) and LiNO3 as dual synergistic additives, and successfully constructed a Li3N/Li2SO3/LiF-rich SEI on Li metal anode. By utilizing the high binding energy between PMS and NO3-, the crystallization/ionization equilibrium of LiNO3 is disrupted, increasing the solubility of LiNO3 by nearly 4 times (1.2wt%) in carbonate electrolyte. In addition, LiNO3 and PMS both have low LUMO energy levels and can decompose on SEI to generate Li3N, Li2SO3 and LiF. Under the synergistic effect of Li3N with excellent rate performance and Li2SO3/LiF with high interfacial energy, the Li//Li symmetric battery can stably cycle for over 700 h at 1.0 mA cm-2 and 1.0 mAh cm-2 conditions. Li//LFP (10.41 mg cm-2) and Li//NCM811 (10.82 mg cm-2) full batteries can stably cycle for 800 cycles at 1 C with a capacity retention rate of 70% and for over 200 cycles at 0.4 C with a capacity retention rate of 80%, respectively.