Hydrogel is a hydrophilic polymer cohesive system with a three-dimensional reticulated structure, which has the characteristics of high water content, high water retention, adhesion and good biocompatibility, and is widely used in biomedical materials. Hydrogel coatings retain the advantages of hydrogel and pave the way for improved lubricity, biocompatibility and flexibility of solid surfaces. By changing the formulation of hydrogel, it is also possible to give the surface of solid substrate such as antibacterial and antifouling properties and other multifunctionality, which has a widespread development in the biomedical field. With the development of the medical treatment, implantable and interventional medical devices are increasingly used to treat a variety of diseases, such as stents and medical guidewire catheters. However, the materials commonly used for various medical devices have poor lubrication and antifouling properties, which experience high friction with surrounding tissues and are likely to suffer biofouling, resulting in a series of side effects such as inflammatory reactions and thrombosis. Therefore, these implantable medical devices usually require complex surface modifications during application to improve performance and biocompatibility. Among a variety of surface modification techniques, hydrogel coatings have received extensive attention with their structural stability, biocompatibility and controlled thickness. Recently, hydrogel coatings with controlled thickness and tough adhesion have been achieved on various substrates, which have more possibilities for the modification of hydrogel coatings on the surface of implantable medical devices.