Strain rate is an important factor affecting the mechanical properties and acoustic emission characteristics of cemented backfill. In order to study the strain rate and the acoustic emission response of cemented backfill, the acoustic emission test of cemented backfill under uniaxial compression was carried out. The strain rate and the timing characteristics of acoustic emission during loading were studied. The correlation between strain rate and acoustic emission timing characteristics as well as the intrinsic relationship between the two trends were discussed, which further revealed the crack evolution law of the cemented backfill under load. Results show that the strain rate and ringing count rate of cemented fillings had the variation trend and phase characteristics of “up→down→steady→up” in the whole process of deformation, and the correlation between them was high. The internal rupture of the cemented backfill was caused by the friction between the aggregate and the fracture evolution of the cemented material. The strain rate played a dominant role in the acoustic emission characteristics. The strain rate in the stage of plastic yield and instability, showed obvious abruptness, which could provide effective precursor information for the prediction of cemented backfill fracture. The combination of acoustic emission ringing count rate, quiet period, and expansion could better reflect the rupture of cemented backfill. The research results can lay a theoretical foundation for the study of mechanical properties of cemented backfill.