The invention discloses a method for preparing a silicon-based rutile TiO2 film by pulse laser depositing, which comprises the procedures of: placing a cleaned Si chip and a TiO2 target with the purity no less than 99.9 per cent into a vacuum chamber; vacuuming the vacuum chamber to the status of 1 multiplied by 10-3 minus 6 multiplied by 10-3 Pa; inputting 0.5Pa to 5Pa argon, or 0.05Pa to 0.5Pa oxygen and heating the Si chip to 500 to 800 DEG C; focusing the laser from a KrF quasi-molecule laser machine onto the TiO2 target (the energy of the laser beam is 340 to 750mJ, the repeating frequency of the laser is 1 to 10 Hz); launching the TiO2 plasma generated onto the Si chip and obtaining rutile nanometer TiO2 film. The invention adopts a TiO2 target to change the parameters in the pulse laser depositing, thus growing directly with pure rutile TiO2 film on silicon chips. The method is simple and is even in the distribution of film components and is good in crystallization performance,which can be linked well with traditional semiconductor processes, and has a good application prospect.