The invention discloses a gel battery electrolyte. The gel battery electrolyte comprises the ingredients in percentage by mass: 4-8% of silicon dioxide, 0.6-2% of anhydrous sodium sulfate, 0.2-0.8% of phosphoric acid, 21.5-38.4% of sulfuric acid and the balance of water. The invention also discloses a preparation method for the gel battery electrolyte, wherein the preparation method comprises the steps of (1) mixing silicon dioxide with water, and preparing a gel mother liquid under a high-speed shearing effect; (2) preparing a dilute sulfuric acid solution, and adding anhydrous sodium sulfate and phosphoric acid to obtain a mixed solution; and (3) adding the obtained gel mother liquid into the mixed solution, and rapidly stirring to obtain the gel battery electrolyte. Due to the synergetic cooperation and the reasonable adding sequence of the materials with the proportion, the prepared electrolyte is capable of effectively eliminating hydration layering, long in cycle life and excellent in charging-discharging performance at a low temperature environment; and meanwhile, the electrolyte system is stable, low in cost, and good in the operational performance.