NOVELTY - Preparing composite photosynthetic bacterial fertilizer involves inoculating purple sulfur bacteria strain in culture medium at 25-30 degrees C for 7-10 days in light. Pseudomonas is cultured by streaking at 25-35 degrees C for 3-5 days. The inoculated purple sulfur bacteria is passaged at 25-35 degrees C in light (light intensity 1000-3000lx) for 7-10 days. The culture is tested for viable cell count ( greater than or equal to 600 million cfu/ml) at optical density 650 less than or equal to 1.2 to obtain seed culture liquid. The obtained colonies of Pseudomonas are inoculated in culture medium at 25-35 degrees C for 3-5 days in light.    USE - Method for preparing composite photosynthetic bacterial fertilizer (claimed).    ADVANTAGE - The method enables to prepare composite photosynthetic bacterial fertilizer, which prevents diseases and degrade drug residue in soil, and has high stability.    DETAILED DESCRIPTION - Preparing composite photosynthetic bacterial fertilizer involves inoculating purple sulfur bacteria strain in culture medium at 25-30 degrees C for 7-10 days in light. Pseudomonas is cultured by streaking at 25-35 degrees C for 3-5 days. The inoculated purple sulfur bacteria is passaged at 25-35 degrees C in light (light intensity 1000-3000lx) for 7-10 days. The culture is tested for viable cell count ( greater than or equal to 600 million cfu/ml) at optical density 650 less than or equal to 1.2 to obtain seed culture liquid. The obtained colonies of Pseudomonas are inoculated in culture medium at 25-35 degrees C for 3-5 days in light (light intensity 1000-3000lx). The culture is tested to obtain viable count of (1.5 million cfu/ml) at optical density 660. The inoculated purple sulfur bacteria is passed in culture medium in ratio of 1:3-1:5. The Pseudomonas is passaged in culture medium in ratio of 1:10-1:20 in light at 25-35 degrees C. The light intensity is 1000-4000lx. The culture is stirred at 120 revolution per minute in culture tank. The culture tank is added with sodium thiosulfate (300g/L) and continued adding till concentration reached to 1-3g/L and cultured for 5-7 days. The culture is tested at optical density 650 to obtain viable cell count of greater than or equal to 6 billion cfu/ml. The viable cell count of purple sulfur bacteria not less than or equal to 2.5 billion cfu/ml and Pseudomonas is not less than or equal to 2 billion cfu/ml. The obtained product is canned and packaged.