Abstract: Taking the Cynodon dactylon seed as the research object, different contents of planting soil, organic fertilizer and biochar were added into the porous anti-erosion particles to form the mixed matrix and the germination experiment was carried out.The effects of single factors and their combined effects on Cynodon dactylon seed germination and seedling growth were evaluated, in order to provide reference for developing new engineering-ecological coordinated technology for bank protection.The results showed that the content of planting soil, organic fertilizer and biochar had a certain impact on seed germination, and the influence effects ranked in order of higher to lower were planting soil, organic fertilizer and biochar.After comprehensive estimation of various influencing factors, the optimum mixing ratio of porous anti-erosion particles∶planting soil∶organic fertilizer∶biochar was 1∶0.20∶0.75∶0.10,which could be used as a vegetation substrate for repairing the ecological environment of the water-level fluctuation zone.