A parallel direct methods of DNS (PDM-DNS) for two-dimensional turbulent thermal convection was created with PDD algorithm for Poisson equation direct solving. DNS calculations of turbulent convection with high Ra were completed on "Tianhe-2" supercomputer, in which iteration time steps are over one hundred million. Effect of calculations is surprised. A calculation scale, which was difficult to achieve a year before, is realized. It shows that turbulent convection flow with different high Ra number are completely different. This work provides a valuable method for massively parallel computing and numerical simulation of turbulent convection with high Ra number.