Abstract: The positron trapping behavior of Ag precipitates at 823 K quenched and 20% deformation Al-4%Ag alloy at low temperature was studied respectively. It was characterized by positron annihilation lifetime spectroscopy (PALS) technology and coincident Doppler broadening spectroscopy (CDBS) in the temperature range of 10~293 K. The positions of the Ag precipitate peak in the Doppler broadening spectrum shows that there are Ag precipitates in both samples. The components of the lifetime spectrum analysis results show that the change of Ag precipitates with the measurement temperature has a strong temperature dependence at the range of 170~273 K. However, for two specimens with different types of defects, in the measurement data below 170 K, a difference in the positron trapping ability of the Ag precipitates in the sample was observed. With the decrease of the measurement temperature, both the positron lifetime and it’s intensity of the Ag precipitates in the quenched specimens begin to stabilize and lose their dependence on temperature. In the measurement below 170 K, the precipitating ability of the Ag precipitates in the deformed sample still has a strong temperature dependence, but the change amplitude is gradually weakening. In the end, when the measurement temperature increased to around room temperature (273~293 K), more and more positrons escaped from the Ag precipitate, gradually transitioned back to the free state or trapping by other deep traps, and lost the temperature dependence.