The invention discloses a compound 
microorganism bacterium agent for degrading 
petroleum hydrocarbon as well as a preparation method and application of the compound 
microorganism bacterium agent. The compound 
microorganism bacterium agent is prepared from active 
acinetobacter KJ-1 with the preservation number of CGMCC (China General 
Microbiological Culture Collection Center) No.20664, 
Providencia reevei L1 with the preservation number of CGMCC No.16526, bacillus SWH-1 with the preservation number of GMCC No.1950 and 
sphingobacterium SWH-2 with the preservation number of CGMCC No.1951. The 
petroleum hydrocarbon degradation composite 
microbial agent prepared by the invention can effectively degrade 
petroleum hydrocarbon substances in soil and oily 
sludge sand, can be effectively applied to 
biodegradation treatment of petroleum-polluted soil, and does not cause secondary 
pollution to the 
ecological environment of the soil; the synergistic effect of the 
acinetobacter live KJ-1, the province reevesii L1, the bacillus SWH-1 and the 
sphingobacterium SWH-2 is fully utilized, the final degradation efficiency of the petroleum hydrocarbon is improved, the preparation process of the 
solid microbial inoculum is simple and easy to operate, the cost is low, and the 
solid microbial inoculum is suitable for industrial production. The method has a wide application prospect in the field of 
bioremediation of petroleum-contaminated soil and 
petroleum product leakage accident sites.