The invention belongs to preparation of a microbial agent and especially relates to paenibacillus mucilaginosus and a method for producing a compound microorganism bacterium agent by utilizing the same. After the paenibacillus mucilaginosus CGMCC No. 7240 is selected and fermented, the fermentation liquid is combined with oligochitosan and corresponding microelements to form the compound microorganism bacterium agent. According to the invention, the problems of no mature product of environmental-friendly bio-agricultural preparation and large potential market gap in the prior art are solved; the produced pollution-free green biological preparation has double functions of pesticide and fertilizer; therefore, in use, the times of fertilizer application and the use cost can be reduced and the synergistic effect of mutual promotion and mutual improvement between the pesticide and the fertilizer is achieved; and as a result, obvious environmental value and social benefits can be generated.