Sarcopenia, commonly observed in diabetes, is characterized by reduced muscle mass and function. However, the relationship between muscle oxygen saturation (SO₂) and sarcopenia remains unclear. Photoacoustic imaging (PAI) offers a promising method for assessment. This study aimed to evaluate SO₂ distribution in diabetic sarcopenic patients using PAI and explore associations with clinical parameters. Type 2 diabetes patients (≥ 10 years) underwent PAI of the gastrocnemius and vastus lateralis muscles. Sarcopenia was diagnosed by AWGS 2019/2020 criteria. SO₂ values stratified patients into hypoxia, intermediate, and hyperoxia groups. The study included 64 sarcopenic and 115 non-sarcopenic patients. Mean SO₂ was significantly lower in sarcopenia (63.28 % vs. 66.26 %, P < 0.001). PAI-measured SO₂ was an independent protective factor (β = -0.10, P = 0.001). In conclusion, PAI-assessed SO₂ is associated with sarcopenia and may serve as an early screening biomarker.