Despite the promising outcomes observed in individual applications of biochar and polyvinyl alcohol (PVA) in soil, the impact of their combined usage remains inadequately understood. This study systematically explores the effects of concurrent biochar and PVA application on key soil parameters, including pH, water-holding capacity (WHC), and dynamic moisture content (MC), and the photosynthetic resilience and growth of the cyanobacterium Microcoleus vaginatus in a desert soil. Biochars, generated at different pyrolysis temperatures (300-600 degrees C), were applied to the soil at varying rates (1%-6%), while PVA was introduced at a mass percentage of 0.05%. The photosynthetic resilience and biomass accumulation of M. vaginatus in different treatments were examined every 7 d during the 28-d exposure to dry conditions after 60-d water supply. The combined application of biochar and PVA resulted in a reduction of soil pH, coupled with significant improvements in WHC and dynamic MC. Moreover, this combined approach exhibited superior effects on the photosynthetic resilience and crust thickness (0.9-3.5 mm) of M. vaginatus compared to the application of biochar and PVA in isolation. Incremental increase in biochar application rate from 0% to 6% demonstrated a notable enhancement in the chlorophyll a content of M. vaginatus. Cyanobacterial crust thickness and exopolysaccharide content exhibited positive correlations with biochar application rate. Thus, combined application of biochar and PVA is cost-effective for enhancing soil properties and cyanobacterial biomass, which is of significance for combating desertification.