Abstract: Aluminum alloys have gained more and more widespread applications for their excellent properties,but their insufficient high-temperature creep resistance limits their service life in high-temperature environments. A two-dimensional representative volume element finite element model was constructed for the simulation of creep behavior based on the metallographic photographs of Al-12Si-4.5Cu alloy before and after modification,and the creep performance of Al-12Si-4.5Cu alloy was tested at 350 ℃ and 15-25 MPa. The creep finite element results show that the rod eutectic silicon has better creep resistance than the spherical eutectic silicon,and the steady-state creep rate of the unmodificated model is 51.4%-54.4% lower than that of the modificated model under the stress of 15-25 MPa. The results show that the creep performance of the unmodificated alloy is better than that of the modificated alloy,which is manifested by lower steady-state creep rate,longer creep life and larger creep strain,and the simulation calculation results are basically consistent with the test results,indicating that the use of two-dimensional representative volume element finite element model for creep simulation has a certain degree of feasibility.