Heat transfer process in data center is a typical complex heat exchange network between multiple cold streams and multiple thermostatic heat sources. In order to improve the thermal environment in data center, it is significant to optimize the heat transfer process. In this paper, a modified virtual distribution and mixing entransy analysis method is studied to calculate the virtual distribution and mixing entransy dissipation of the heat transfer process in data center, and this heat exchange network between multiple cold streams and multiple thermostatic heat sources can be equivalent to a two-steam heat transfer. The optimization analysis results of a typical heat transfer process in data center show that the entransy-dissipation-based thermal resistance with virtual distribution and mixing is corresponding to the heat transfer rate.