Recently, Hangzhou Yunxiang Network Technology Co., Ltd. (hereinafter referred to as “Yunxiang” successfully won the bid of China National Everbright Bank Co., Ltd. “Domestic L/C Blockchain Project” to further promote the exploration and practice of blockchain technology in the field of trade finance. The development of the financial ecosystem of commercial banks. Due to the long-term stay in the form of paper opening, the traditional letter of credit is easy to lose and tampering. The information transmission process is lengthy and cumbersome, and users have to pay high fees for information transmission. The low security, low efficiency and high cost of the traditional letter of credit business caused by these factors have long been a long-term pain point in the industry. The cooperation between Yunxiang and China Everbright Bank Co., Ltd., through the technical characteristics that cannot be tampered with by blockchain technology, will create new trust mechanisms, which will bring many new changes to the domestic letter of credit business.