As the desire underfill material for the application on the infrared focal plane detector (IRFPA), the low-temperature epoxy resin with tetrahydrofuran (THF) copolyether modification was prepared by elastic epoxy and varying content of curing agent (C).The thermal and mechanical properties of the cured samples were studied using dynamic mechanical analysis (DMA) with different testing modes and temperature condition.Discrepancies of elastic modulus were found through the liner fitting to strain-stress curves, which were measured by tensile loading fixture with a gradually increased static force.As a dynamic test, temperature scanning mode was employed to characterize the glass transition temperature (Tg) of final samples, with which related data ranged from 30 to 46 ℃ was indirectly obtained from the value of loss modulus peak position.Significantly, DMA methods could be efficiently used to simulate the practically changed temperature environment and timely record the testing data, which is significant for studying the chip failure mechanism in IRFPA.