Abstract: A rhizosphere bacteria-Bacillus amyloliquefaciens WJ22 stored in our laboratory was a plant growth-promoting rhizosphere bacterium. In the present study, ripe cow manure compost and rapeseed cake as raw materials, cassava residue and eucalyptus slag as addition materials were chosen from agriculture wastes in Hainan province to solid fermented strain WJ22 and the bio-organic fertilizer made from this strain was prepared. The results showed that strain WJ22 could grow well in the mixture contain 65% of ripe cow manure compost, 15% of rapeseed cake, 20% of cassava residue, and 20% of eucalyptus slag. The strain number is more than 9 × 108 cfu/g dry weight at the ending of composting process and were far more than the national solid bio-organic fertilizer standard (2 × 107 cfu/g dry weight). Pot experiment results showed that the bio-organic fertilizer made from WJ22 could efficiently promote the growth of banana.