The invention discloses high-strength rubber and a preparation method thereof. The rubber is prepared from 30-60 parts of butadiene-acrylonitrile rubber, 20-50 parts of chloroprene rubber, 8-25 parts of natural rubber, 3-11 parts of titanium dioxide, 2-7 parts of talcum powder, 3-7 parts of zinc oxide, 8-15 parts of chlorinated polyethylene, 6-10 parts of octyl phenolic resin, 15-25 parts of reinforcing filler, 5-13 parts of vulcanizing activator, 0.8-1.8 parts of vulcanizing agent, 1.2-3 parts of vulcanizing accelerator, 6-10 parts of plasticizer and 2-4 parts of anti-aging agent. A coating has the advantages of being high in strength, resistant to high-pressure shock, not prone to breaking, good in wide-temperature range adaptability, capable of meeting wide-temperature range utilization requirements, reliable in quality, durable in use, low in cost, easy to prepare and suitable for large-scale production.