Hydrogels are widely used in various fields due to their high swelling ratio and high water content. However, the shortcomings of weak mechanical properties limited its development in high-load fields such as tissue engineering, soft robots, and wearable electronic devices. The methods and research progress in preparing high-strength hydrogels were summarized, including nanocomposite hydrogels, double-network hydrogels, polymer microsphere composite hydrogels, and hydrophobic association hydrogels. The characteristics of each type of high-strength hydrogel were discussed and the problems existing in the current research were pointed out. At the same time, the future research direction of high-strength hydrogels was prospected.