Highly dispersed nickel nanoparticles were successfully prepared by reduction of Ni-Al layered double hydroxide precursor (NiAl-LDH) supported on nitric acid modified carbon nanotubes (HCNTs). The physicochemical properties of materials were investigated by powder X-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed decomposition (TPDE), temperature programmed desorption (TPD), transmission electron microscopy (TEM), low-temperature nitrogen adsorption-desorption experiments, and X-ray photoelectron spectroscopy (XPS). The results revealed that in the synthesis process of NiAl-LDH and HCNTs composite, L-cysteine could improve the attachment of NiAl-LDH on the HCNTs as bridging linker and inhibit the growth of NiAl-LDH crystallites, thus leading to the formation of highly dispersed and uniform Ni nanoparticles with the small particle sizes. Compared with HCNTs-supported Ni catalyst prepared without the addition of L-cysteine, this highly dispersed Ni catalyst exhibited enhanced catalytic performance in liquid phase hydrogenation of o-chloronitrobenzene to o-chloroaniline.