This application provides an electrolytic solution and a lithium metal battery containing the electrolytic solution. The electrolytic solution includes a lithium salt, an organic solvent, and an additive. The additive includes a sultam compound represented by Structural Formula I. R is selected from substituted or unsubstituted C1 to C10 hydrocarbyls, where a substituent is selected from a phenyl, C1 to C6 alkyls, or C1 to C6 alkenyls. X is a sulfur atom or a phosphorus atom. R1 and R2 each are independently selected from an oxygen atom, a fluorine atom, a chlorine atom, a bromine atom, and substituted or unsubstituted C1 to C10 hydrocarbyls. Both R1 and R2 are not oxygen atoms concurrently.