The invention discloses a rubber insole and a preparation method thereof. The rubber insole is formulated according to the following weight components: natural rubber 60-80, styrene-butadiene rubber 20-40, rubber accelerator DM1.2-1.5, rubber accelerator Agent M0.8‑1, rubber accelerator H1.2‑1.5, zinc oxide 5‑8, stearic acid 5‑8, PEG active agent 1, wear-resistant particles 1, MB antifogging agent 0‑1.5, white ointment 8-11, foaming agent 5-8, soda 12-15, sulfur 1.2, paraffin 2-3, SPC anti-aging agent 0-1.5. The method comprises the following process steps: preparing a rubber foam sheet; preparing an upper mold and a bottom mold; and demoulding. The beneficial effects of the invention are: environmentally friendly formula, simple process, good air permeability, deodorizing and environmentally friendly, no breakage, light overall weight, and comfortable to wear.