In order to solve the problems of gas generation during battery high-temperature storage, poor high-temperature cycle performance and the like of the existing lithium ion battery electrolyte, the invention provides lithium ion battery nonaqueous electrolyte. The lithium ion battery nonaqueous electrolyte contains a compound with the structure shown as a formula I shown in description, wherein in the formula I, R1, R2, R3 and R4 are respectively and independently selected from hydrogen atoms, fluorine atoms, cyano-groups, alkyl or halogenated alkyl with the carbon atom number being 1 to 5, oxygen-containing alkyl with the carbon atom number being 1 to 5 and silicon-containing alkyl with the carbo atom number being 1 to 5; X is a -O-R5-CN group; R5 is hydrocarbyl or halogenated alkyl with the carbon number being 1 to 5; m, n, z and y are an integer being 0 or 1; m+n+y+z is not equal to 0. When the nonaqueous electrolyte is used for the lithium ion battery, the decomposition of the electrolyte on the electrode surface can be inhibited; the high-temperature storage performance of the battery is improved; the generated gas is little; the expansion rate of the battery is small, so that the high-temperature cycle performance and the high-temperature storage performance of the lithium ion battery are effectively improved.