The Modular Tube-type Irradiation Rig(MTIR) is designed to conduct various material performance tests in high flux region of the High Flux Engineering Test Reactor(HFETR).Using Ansys CFX to establish a mathematical model,a simulation study on thermo-technical characteristics of MTIR is performed.The analysis shows that the results from the material irradiation test in HFETR are in good agreement with the analysis results by Ansys CFX,which shows that the results about the steady-state thermal analysis are correct,and it provides the basic research on the design of MITR.