The invention provides slimming gel and a preparation method thereof. The slimming gel is made from, by weight, 31.78% of water, 5% of tea leaf extract, 2% of a marine biotical, 2% of caffeine, 7% of Hamamelis mollis extract, 3% of lotus leaf extract, 3% of aloe emodin, 5% of Rheum palmatum root extract, 5% of ginger extract, 5% of Paullinia cupana, 6% of polydimethylsiloxane, 8% of a mineral oil, 2.5% of PEG-100 stearate, 2.5% of glycerol stearate, 0.5% of stearic acid, 1% of cetearyl alcohol, 1% of ceteareth-25, 0.5% of xanthan gum, 3% of glycerol, 3% of Aloe vera leaf extract, 2% of propylene glycol, 0.02% of hyaluronic acid, 0.4% of phenoxyethanol, 0.2% of methylparaben, 0.1% of propyl 4-hydroxybenzoate, and 0.5% of aluminum hydroxide. The slimming gel is applied to the human acupoints for hot compress, has good slimming effect, is convenient to use and god in safety, and is free of side effects.