Photothermal materials and adsorbents are the main components of solar-driven seawater desalination. This being so, the objective of the research was to determine the effectiveness of a photothermal membrane made of biochar from pruning residues for the reduction of seawater salinity. For the salinity reduction treatment, a stainless steel continuous cell evaporation system including photothermal membranes with 150 g of pruning biochar was constructed, and the physicochemical parameters of the seawater were measured both before and after the treatment. The desalination process was carried out for 6 h per day (10:00 a.m. to 4:00 p.m.) for 3 consecutive days. The results showed a reduction in the values of sulfates, phosphates, turbidity, total solids, dissolved solids and chlorides, with a salinity reduction efficiency of 91.08 %, with a radiation of 0.98 kW/m² and a relative humidity of 49 %. Finally, it was concluded that the evaporation system using pruning biocarbon membranes improved the values of the physicochemical parameters of seawater and could be used as an alternative solution to water scarcity in rural coastal populations.