1. Market Wholesale: Many cities have specialized food wholesale markets. You can go to the local food wholesale market to find a soybean milk supplier. There are usually several soybean milk suppliers in these markets, and you can contact them to know the price and delivery method.

2. Wholesale of farmers' markets: Some farmers' markets also have soybean milk suppliers, who generally produce soybean milk by themselves and wholesale it to the surrounding vendors and restaurants. You can go to the local farmers' market and ask about the supply of soybean milk.

3. Online wholesale platform: With the development of the Internet, many food wholesalers began to sell products online. You can search for soybean milk wholesalers on some well-known e-commerce platforms, browse their products and prices, and contact for purchase.