Due to good biocompatibility and mechanical properties similar to those of natural biological tissues, hydrogels have been widely used in biomedical fields. With the development of biomechanics, more and more researches have found that the viscoelastic tunable composite hydrogels based on dynamic covalent bonds can better simulate the viscoelastic mechanical properties of biological tissues and natural extracellular matrix over time due to their superior biomechanical properties and stimulus responsiveness. This review summarizes in detail the applications of viscoelastic tunable composite hydrogels based on different types of dynamic covalent bonds (imide bonds, disulfide bonds, borate ester bonds, etc.) in the fields of regulating cell function, affecting tissue regeneration and repair, as well as drug delivery. The challenges and opportunities for future research are also proposed.