A series of water–rock interactions occur during hydraulic fracturing. The key questions concern how these interactions affect the tight reservoir and influence natural gas production. For unconventional hydrocarbon reservoirs, the effects of water–rock interactions on the reservoir begin during diagenesis, where compaction and cementation alter and degrade the reservoir, leading to formation damage. Formation damage also occurs during production stages of unconventional reservoirs, including drilling, hydraulic fracturing, and well completion. Compared with other processes, reservoir damage is more pronounced during hydraulic fracturing. The incompatibility between fracturing fluids and reservoir rocks often leads to formation damage through water–rock interactions, impeding hydrocarbon migration and production. As an external fluid, the injection of large volumes of fluid disrupts the equilibrium of the formation environment, leading to reservoir damage. Clay minerals, second only to quartz in abundance within tight sandstone reservoirs, play a critical role in determining the stability and effectiveness of hydraulic fracturing. Based on laboratory and field experiments, this chapter investigates the impacts and damage mechanisms of fracturing fluid-tight sandstone interactions during hydraulic fracturing, focusing on clay mineral instability and scale-induced pore blockage.