Hydrogels are a class of polymeric network materials embedded in a water-rich environment. They are widely applied in drug delivery, actuator, and sensor. However, conventional hydrogels encountered limits from their poor mechanical property. Recent researches in hydrogels have been focusing on mechanical enhancement, ranging from design of microstructures to adjustment of compositions in hydrogels. Here, the design and fabrication strategies of high-strength hydrogels, as well as major progress in their typical strength-support applications are systemically reviewed.