The three-dimensional (3D) hierarchical porous structure is ideal for constructing high-performance electrode materials and offers advantages such as large surface area, stable structural integrity and efficient ionic transport. In this report, we prepared a novel wafer-like 3D porous structured NaTi₂(PO₄)₃/C by a facile self-assembled strategy. The NaTi₂(PO₄)₃ crystal was not only coated by a nanoscale carbon layer but was also embedded in a microscale carbon network, which self-assembled into a secondary particle in a plate-like shape. The hierarchical carbon in the plate-like particle constitutes a 3D porous framework with a bicontinuous electronic conductive skeleton, showing a wafer-like structure. When used as an anode in an aqueous system, the wafer-like composite exhibited better sodium intercalation kinetics and enhanced high-rate capability than nonporous samples. Moreover, a full aqueous rechargeable sodium battery was fabricated using the wafer-like NaTi₂(PO₄)₃ as the anode and Na_0.44MnO₂ as the cathode. The cell exhibited superior high rate property and an ultralong-life performance, which delivered 64% capacity at 30 C and retained 67% capacity after 400 cycles at alternate 50 and 5 C. In view of the highly efficient electron/ion transport pathways and robust structure stability, the wafer-like structure is put forward as a new strategy for nanoarchitecture tailoring to achieve high-performance electrodes.