FPGA, short for Field-Programmable Gate Array, is a type of integrated circuit that can be programmed and configured by users or designers after manufacturing. Due to its reconfigurability, FPGA achieves instant prototyping and debugging capabilities in a wide range of applications, which has led to the growing adoption of FPGA in sectors including healthcare, autonomous driving, aerospace, and the military industry. Computer-Aided Design (CAD) refers to a collection of software programs that assist designers in the FPGA design process. With the recent breakthrough in Artificial Intelligence (AI), an increasing number of AI-based methods are being proposed to enhance the CAD flow across different stages, from the front-end to the back-end processes. In this chapter, we provide a comprehensive introduction to AI-powered solutions in the FPGA CAD design flow, focusing on crucial steps such as high-level synthesis (HLS), logic synthesis, placement, and routing. Comparisons between AI-based methods and conventional methods will be generated to show the advantages of the integration of AI in different steps. This chapter will include five major topics: (1) overview of FPGA CAD flow, (2) AI-powered HDL (hardware description language) generation, (3) AI-powered logic synthesis, (4) AI-powered placement, and (5) AI-powered routing.