Surface-enhanced Raman spectroscopy (SERS) technique plays an important role in molecular recognition fields due to its highly sensitive and high-resolution. As an emerging low-cost, high machining accuracy, and high-flexibility processing method, femtosecond laser direct writing processing has been widely used in the field of preparing SERS substrates. This work introduces four methods of preparing SERS substrates by femtosecond laser direct writing, including femtosecond two-photon reduction, femtosecond laser cutting metal, femtosecond laser cutting-sputtering, and femtosecond laser 3D printing. The article introduces the performance and application scenarios of each method in preparing SERS substrates and illustrates the advantages of femtosecond laser direct writing processing in preparing SERS substrates, aiming to provide a reference for future related research.