The increasing maturity of Internet information technology has led to the rapid rise of blockchain technology. In essence, a blockchain is a shared database. In recent years, blockchain technology has attracted the attention of the public and society. With the continuous development of the market economy, many domestic enterprises have grown in size. At the same time, companies are also faced with various risks, and business risks will have a great impact on the company’s production. This article aims to prevent the business risk of Internet information security platform enterprises based on blockchain technology. Through the PoS algorithm, PoW algorithm, secure hash algorithm, and the principle of direct trust, the Internet information security platform is designed. Firstly, the platform is used for a business risk test with a small company, and the platform satisfaction survey is conducted on the employees of the company. The test results show that the subplatform design reduces the business risk of the company by 5%–10%, and employee satisfaction is high. The signature simulation of this algorithm under the same conditions as the SMRA and RSAR methods is also carried out. The results show that the performance of this algorithm is better. This study opens up a new path for small and medium-sized enterprises to prevent business risks.