Photovoltaic (PV) deployment on degraded lands synergizes renewable energy with ecological restoration, yet its specific impacts in fragile karst ecosystems remain poorly understood. This study provided the first evidence of how a flexible PV array modifies the surface microclimate and soil environment in a karst rocky desertification region of Southwest China. Microclimate and soil parameters were synchronously monitored: underneath (UPP), between (BPP), and outside (CK) the panels over a complete growing season. Results showed that the PV array created strong spatial heterogeneity in radiation and light, with UPP receiving over 90% less global horizontal irradiance than CK, while BPP experienced occasional light enhancement due to panel reflection. Air temperature under the panels was significantly buffered: the regression slopes were 0.937 for UPP and 0.902 for BPP; both were significantly less than 1 (p < 0.001), confirming that the PV array significantly reduced the amplitude of temperature fluctuations. This bidirectional temperature buffering (cooling during hot periods, warming during cool periods) was particularly pronounced during hot periods, with peak temperatures reduced by up to 5.0 degrees C in UPP relative to CK. Relative humidity in UPP increased by up to 3.3% compared to CK, and evaporation was reduced by over 80%. Wind patterns were restructured, with pronounced channeling effects in BPP and more diffuse flows in UPP. Soil temperature was consistently lower and less variable under the panels. Soil moisture responses were depth dependent: at 10 and 30 cm, UPP showed similar or slightly lower moisture than CK, while at 20 cm, moisture increased notably during multiple months, suggesting lateral subsurface flow and reduced evaporation as key mechanisms. These modifications disrupted the typical warming-drying feedback loop in karst soils, creating more favorable conditions for vegetation recovery. Our findings demonstrate that flexible PV arrays can actively regulate microclimate and soil environments in degraded karst landscapes, supporting the potential of eco-photovoltaic systems to combine renewable energy generation with ecological restoration. Longterm monitoring and vegetation studies are needed to confirm the sustainability of these benefits.