The limited lithium resources and the great risk of conventional liquid-state electrolyte can affect the development of all-solid-state sodium-ion batteries. As a core component of all-solid-state sodium battery, sodium-ion solid-state electrolyte can play an important role in improving the safety and electrochemical performance of the battery. NASICON-type solid-state electrolyte Na1+xZr2SixP3-xO12(0≤x≤3) is widely concerned due to its unique 3D open structure and good chemical/thermal stability. This review represented recent research work on the crystal structure, ion transport mechanism, powder preparation methods and sintering methods of Na1+xZr2SixP3-xO12. Two major issues of Na1+xZr2SixP3-xO12 were discussed, i.e., a low ionic conductivity and a poor contact issue at the electrode-electrolyte interface, and the relevant modification methods were summarized. In addition, the optimization scheme of Na1+xZr2SixP3-xO12 and the possible development trend in the future were prospected. This review could play a guiding role in the future research of NASICON solid-state electrolyte and solid-state sodium battery.