The invention discloses a preparation method of a lithium ion battery gel electrolyte and a lithium ion battery containing the gel electrolyte, the gel electrolyte comprises a liquid state electrolyte, a polymer component and an initiator, the polymer component contains three types of molecules of A, B and C, wherein the type A molecule is a high liquid state electrolyte adsorption capability polymer, the type B molecule is no more than two of monomers of reaction activity function group, and the type C molecule is more than or equal to three monomers of the reaction activity function group. Compared with the prior art, the three types of molecules of A, B and C in the gel electrolyte enable coexistence, by controlling the gel condition, a pig-cage structure which takes the type C molecule as a center and the type B molecule (or after polymerization) is connected in the gel is formed, the pig-cage structure can lock the gel electrolyte containing the liquid state electrolyte after the type A molecule absorbs the electrolyte inside the pig-cage structure, thereby the gel electrolyte possessing high stereoscopic effect as well as excellent electrochemical performance and safety performance.