To promote the execution efficiency of HLA system which executes on high performance computing (HPC) platform, a self-adaptive communication mechanism, named SACM, is proposed for the hierarchy communication environment of HPC. By this mechanism, the connection with lowest latency can be established from the network information of computing nodes. The shared memory, high speed IB network and Ethernet network can be selected by federates adaptively. Aiming at the demand of shared memory communication between federates within one node, a high speed shared memory communication algorithm based on distributed infrastructure is proposed, and the communication performance can be improved by this algorithm. Experiment result of object attributes value updating latency has shown that the communication performance of RTI executing on HPC platform has been greatly improved.