The invention discloses a titanium nitride film with a highly preferred orientation (100) and growing on a silicon substrate, and a preparation method thereof. A chip subjected to single-sided polishing is taken as a substrate, the chip is placed on a rotary heating table surface, a vacuum cavity cover is covered, a background is vacuumized, nitrogen and argon are charged, charging for the nitrogen and the argon is stopped and vacuumizing annealing is carried out after magnetron sputtering, then a molecular pump is closed, a mechanical pump is closed and a deflation valve is opened after cooling, and a sample is taken out when the temperature of the rotary heating table surface is lowered to normal temperature; and a temperature during film sputtering, and the flow proportions and the total flow of the nitrogen and the argon are adjusted during the magnetron sputtering, and the vacuumizing annealing is carried out, so that the titanium nitride film is finally prepared; and the thickness of the film is controlled through controlling a sputtering power, a working voltage and a sputtering time. The titanium nitride film disclosed by the invention is low in electrical resistivity, high in chemical stability and optical characteristic, suitable for being used as a bottom electrode, and also capable of being applied to various photoelectric detectors; and the method is relatively simple in process.