Nowadays, Direct Power Purchase (DPP) for industrial users has become an important part of the electricity market. This type of transaction usually needs to rely on regulatory agencies to assist in the transaction, and the transaction algorithm is relatively simple. Blockchain technology based on encryption algorithm has the function of distributed ledger, which can make DPP more transparent and reliable. This paper proposes a DPP transaction method, which incorporates the peak shaving characteristics of industrial users and the green certificate system into transactions, and completes related transactions on the blockchain platform. First, establish a DPP market structure based on blockchain technology. Second, establish a DPP transaction mechanism based on green certificates and peak shaving characteristics. Simulation results for four cases show that the proposed method can respond to peak shaving capacity and bring more profit to renewable energy companies.