The invention discloses a 
biological agent capable of repairing heavy 
metal contaminated soil. The 
biological agent comprises 
rhodopseudomonas palustris ATCC17001 strain, N strain and NO.37 strain of 
rhodopseudomonas in 
photosynthetic bacteria and 
rhodobacter sphaeroides ATCC17023 strain, T2 strain and NO.55 strain of 
rhodobacter. The invention also discloses a preparation method of the 
biological agent capable of repairing the heavy 
metal contaminated soil, wherein the production process is a process for amplification culture of microorganisms step by step. The biological agent has the beneficial effects that the 
endurance capacity of functional microorganisms to 
heavy metals is high, and the functional microorganisms still maintain the activity and efficiently repair the heavy 
metal seriously contaminated soil; the biological agent not only can adsorb and accumulate the 
heavy metals and can convert the forms of the 
heavy metals, so that the heavy metals are changed into a 
stable state from a 
water soluble state which is big in environment hazards; and the biological agent is simple in preparation, wide in application range, low in treatment cost, short in 
treatment time, complete in treatment and strong in 
operability, and can be popularized and applied in a wide range.