Abstract: To investigate damage precursor characteristics in dry and water-saturated sandstone under uniaxial compression, uniaxial compression tests combined with acoustic emission (AE) monitoring were conducted. The analysis focused on five aspects: AE b-value, dominant frequency, dominant frequency entropy, ring-down counts, and multifractal parameters. All five methods revealed clear damage precursor signatures: the AE b-value decreased significantly, with a large number of signals below 1.1 appearing; the dominant frequency bands of low-amplitude signals broadened noticeably, accompanied by the emergence of high-amplitude, low-frequency AE signals; the dominant frequency entropy increased abruptly and sharply; AE signals with high ring-down counts appeared frequently; and the multifractal parameters Δα and Δα0 exhibited sudden large increases and decreases, respectively. The damage precursor response coefficients (DPRC) derived from these methods indicated that dry specimens showed higher DPRC values than saturated specimens, and damage precursors in saturated specimens appeared later than in dry specimens. The dominant frequency entropy demonstrated better stability compared to other identification methods. The median and mean values of Pearson's correlation coefficients for different damage precursor identification methods in dry and saturated sandstone followed the order:Δα > Δα0 > b-value > entropy-value. Therefore, the multifractal parameters Δα and Δα0 can serve as primary indicators, while the AE b-value and entropy value can be used as supplementary criteria. These findings provide theoretical support and a technical framework for monitoring rock stability in water-bearing environments.