This article is mainly introduced the detonation method to prepare TiO2 nanoparticles which use hydrogen-oxygen gas mixture as the explosion source and the titanium tetrachloride as the precursor. It studied TiO2 nanoparticles influenced by different hydrogen concertration. And analyzed the character of prepared TiO2 nanoparticles by XRD and TEM. The results show that the powders are mixed crystal of Rutile and Anatase. It is also found that the relative content of rutile grows larger and the size of grain becomes smaller (about 30~100nm) as the hydrogen content increases, and the TiO2 nanoparticles are mostly spherical. But the dispersion is becomes slightly worse, and the agglomeration appear.