Abstract: Carbon with high electrical conductivity, chemical stability, and capability to alleviate massive volume expansion are the most promising anode materials for sodium and potassium ion batteries. Herein, we develop a defect-rich porous carbon framework (denoted as DRPCF) built with N/O-co-doped mesoporous nanosheets. The as-prepared DRPCF-2/1-700 demonstrates the largest specific surface area with the enormous pore volume and has the highest N/O heteroatom contained active defect sites. Consequently, DRPCF-2/1-700 exhibits superior pseudocapacitive behavior dominated sodium and potassium ion storage performance. As anode materials for sodium and potassium ion batteries, they exhibit high rate and long-term cyclic performance with a mass-specific capacity of 328.2 and 321.5 mAh g⁻¹ at a current density of 1 A g⁻¹ over 900 and 1200 cycles, which outperform most reported carbonaceous materials. The ex-situ Raman spectroscopy results further confirm that the filling and removing of K⁺ and Na⁺ from the site of the electrochemically active defect should be responsible for the high capacity, superior rate, and cyclic performance of DRPCF-2/1-700.