The communication problem of weak and variable signal in troposcatter channel can be effectively solved using MIMO-OFDM technology. This paper analyzes the troposcatter channel characteristics and builds a scattering channel model. Then based on the MIMO-OFDM system model, combined with the actual situation, the parameters are selected and the experimental platform of the MIMO-OFDM system in scattering channel is established. And then under the promise of verification of performance of MIMO-OFDM system, the different transmission rate and different modulation system performance in the same scattering channel are simulated and analyzed. The simulation results show that, the communication capacity increase brought by MIMO-OFDM is obvious and on the premise of meeting the BER requirements, it can realize high speed scattering communication. And they also show than in the high speed transmission, 64QAM modulation is more conductive to reduce BER in scatter communication, meanwhile BPSK, QPSK and 16QAM modulation have little difference. The simulation provides a way for design and optimization of scattering equipment, which has multi rare and multi modem. It provides direction for the realization of large capacity and high reliability scattering communication.