The computational fluid dynamics method is used to establish the model of generated pressure and flow field of high speed gears. The pressure and flow field are calculated and analyzed under different working conditions. Additionally, the twophase flow model of gear oil injection lubrication is established to simulate the rotation pressure field, from which the matching of spray parameters with gear working conditions is studied. The results show that the pressure field generated by high speed gears will hinder the injection jet and result in gear lubrication and cooling failure.