Abstract: Acoustic reflection cover is an important part of the theatre stage performance area with natural sound performance function. Its purpose is to prevent the limited natural sound energy from being absorbed and dissipated by the stage, and to provide good mutual hearing for musicians. In this paper, the measured data in 24 theatres are analyzed to get the statistical characteristics of the acoustic quality parameters before and after assembling acoustic reflection cover, and it is confirmed that significant improvements are achieved in reverberation time, early decay time, strength factor, stage support after assembling the reflection cover.