Abstract: A mathematical model is constructed to describe the dynamic damping performance for a new type of BTG plastic alloy about the temperature-frequency-amplitude. The experimental data of dynamic damping loss factor of BTG plastic alloy were obtained through test of frequency sweep, temperature sweep and amplitude sweep in the dynamic thermal analyzer DMA242. Through the analysis of the experimental data, the amount of damping loss factor is separated 2 components, namely, the amount related only to the frequency and the amount related to both the frequency and temperature .The amount related only to the frequency is described by Kelvin model of fractional derivative and the amount related to both the frequency and temperature is described by Gaussian function. A comprehensive model considering of the temperature-frequency-amplitude is established reference to the above model plus the amplitude factor. The results show that the comprehensive model can accurately describe the experimental data.