信用证凭其独具一格的机制在国际贸易领域发挥着极其重要的作用，而这一作用完全是以信用证的独立性原则为基石的。依据这一原则，银行在付款前只审查单据而不过问货物，只审查单据的表面而不负责单据的有效性。只要单据表面符合信用证，开证银行就必须承担第一性的付款责任。 Credit by virtue of its unique mechanism in the field of international trade plays an extremely important role, and this role is entirely based on the principle of independence of letters of credit as the cornerstone. According to this principle, the bank examines documents only before payment but does not interrogate the goods, examining only the face of the documents and not being responsible for the validity of the documents. As long as the documentary evidence meets the letter of credit, the issuing bank must assume the primary responsibility for payment.