The evaluation of lubricating effect of the transmission lubrication system is an important part in the transmission design. The Ansys-Fluent software is used in this paper. Firstly, the flow field of the single oil orbit of 7DCT transmission is simulated and the mass flow rate of each nozzle is taken as the input condition of the lubricating simulation and analysis in the whole transmission model. Then the whole transmission model is established to facilitate evaluating the lubricating effect of the oil catcher by setting the monitor surfaces at the positions of the oil catcher. The complex oil and gas phase flow field of transmission is simulated and analyzed so that the lubrication effects of three lubricating method are evaluated to achieve the purpose of evaluating the performances of the transmission lubrication system, including the forcing ejective oil lubrication, splash lubrication and oil passage lubrication.