The work aims to obtain TiB2-Ni(Al) composite powder through in-situ synthetic technology. Ni(Al)-based composite powder reinforced by TiB2 ceramic phase with different volume contents was prepared by mechanical alloying method under different ball milling time. The molar ratio of Ni and Al was 1:1. The microstructure and phase of ball-milled powder were analyzed with scanning electron microscopy (SEM) and X-ray diffraction (XRD) respectively. The influence of various ball milling time on the phase evolution of TiB2-Ni(Al) composite powder prepared, microstructure and interfacial bonding between particles was studied. In the process of ball milling, with the milling time prolonging, the plastic deformation between Ni/Al was conducive to atom diffusion and the size of TiB2 ceramic phase particle became smaller and smaller. When the ball milling time increased to a certain extent, the Al powder particles of good ductility would be flattened and its surface area became larger. In such case, the broken Ni powder particles were embedded into Al powder particles to finally form Ni(Al) solid solution. Meanwhile, according to the analysis of XRD, with the ball milling prolonging, Al peak in TiB2-Ni(Al) composite powder was gradually decreased, which revealed that Al constantly diffused into Ni to form a certain amount of Ni(Al) solid solution. Ni(Al) solid solution can be successfully in-situ synthesized by mechanical ball milling technology after a certain milling time, so it is revealed that the inter-diffusion between Ni and Al is in favor of forming Ni(Al) solid solution.