The invention provides an electrolyte and a secondary battery containing the same. The electrolyte is prepared by adding a siloxane compound and a nitrile compound with different contents and an electrolyte salt into an organic solvent. The nitrile compound and the siloxane compound are combined and applied to the secondary battery electrolyte and the secondary battery, so that the effects of thenitrile compound and the siloxane compound are brought into full play, and the cycle performance and the high-temperature storage performance of the secondary battery are further improved.