A novel (Ce-Mg) co-promoted CaO sorbent with multi-dimensional through-hole structure was fabricated by a hydrothermal template method based on natural limestone, to address the evident decline of CO2 adsorption performance during circulation. A trend of first increasing and then stabilizing was achieved for CO2 long-term durability of the as-prepared sorbent by the hydrothermal recrystallization process. The CO2 absorption capacity of the (Ce-Mg) co-promoted tubular sorbents exceeded that of the reference sample without hydrothermal template treatment by ∼ 400% after 30 cycles. 97% of the initial CO2 capacity can be maintained at the 30th cycle. This significant CO2 uptake capacity can be attributed to the multiple synergistic interactions yielded by incorporating g-C3N4 nanotube template with (Ce-Mg) co-doping. A bidirectional gas diffusion channel was constructed based on the inner-outer multi-dimensional connection structure of g-C3N4, which allowed the sorbent to maintain the prominent specific surface area and pore volume during cycles. After 30 cycles, the specific surface area of the limestone-derived sorbents can still remain at 16.31 m2/g. Furthermore, a double vacancy mechanism that can facilitate the gas transport through both the product layer and the surface layer of CaO grains caused by the co-doping of (Ce-Mg) was proposed, which can also promote the electron transport between CaO and CO2. This synergistic strategy proved useful for improving the CO2 uptake performance and cycle durability of CaO sorbents in practical applications.