Abstract: The selection of the finite difference schemes for the convective and diffusion terms of the governing equations of fluid flow has great influence on the computational stability, accuracy and time. In this paper, various combinations of difference schemes, including Central difference, Up-wind, Hybrid, PLDS, QUICK and OPTIMAL, are used to compute the turbulent flow in 3-D room for comparing the stability, accuracy and computational time. A new conception thus obtained reflects in the following aspects. The local use of Up-wind method can eliminate the oscillation of the solution when Reynolds equation is applied in Central difference. Besides, the combination of QUICK and Up-wind method is also proposed to solve the problem that the solution of κ,ε equations diverges when QUICK method is used.