Carbon-based composite materials with tunable, ordered mesoporous structures were prepared via the hydrothermal carbonization/soft-template method, with nickel nitrate as the doping source, straw as the carbon source, and F127 as the soft template. By adjusting the additive amounts of Ni and F127, the mesoporous structure was controllable, and results were obtained that varied from an irregular stripe-like hexagonal, a regular stripe-like hexagonal, mixed hexagonal and cubic, to cubic. With a specific surface area in the range of 339-963 m2 g-1, the percentage of mesoporous structures increased from 39.6% to 58.3%. Ni doped into the carbon skeletons existed in the form of metallic Ni and nickel oxide. Increased amounts of nickel nitrate for doping as well as F127 is beneficial for the generation of metallic Ni during the preparation process. The average particle diameter of Ni decreased when the Ni-doped content was increased, and all the average particle sizes were less than 10 nm after F127 was added. The Nim/CSFn catalyst demonstrated high catalytic activity when used for the hydrogenation reaction of p-nitrophenol (PNP) to p-aminophenol (PAP). The conversion of PNP reached 98.79%, and the selectivity for PAP reached 89.6% for Ni2.0/CSF1.5, with a corresponding apparent rate constant of 1.56 × 10-3 S-1, apparent activation energy of 41.86 kJ mol-1, and with the added benefit that the catalyst could be separated and recycled by applying an external magnetic field.