This article deeply explores the applications and impacts of blockchain technology and smart contracts in the financial industry. First, it outlines the basic principles and characteristics of blockchain technology and smart contracts, and then analyzes their application examples in various financial fields such as cross-border payments, supply chain finance, equity financing and securities issuance, and the insurance industry. The study found that blockchain technology and smart contracts bring significant changes and opportunities to the financial industry by improving transparency, reducing transaction costs, and enhancing security. However, the application of these technologies also faces challenges such as technological maturity, legal and regulatory perfection, and data privacy protection. This article aims to provide valuable references for practitioners, researchers, and policy makers in the financial industry to promote the widespread application and healthy development of blockchain technology and smart contracts in the financial industry.