The invention belongs to the technical field of environment-friendly water treatment, particularly relates to a water purifying agent for wastewater treatment in rubber accelerator M production and further relates to a method for treating rubber accelerator M production wastewater by adopting the water purifying agent. The water purifying agent contains a flocculation water purifying agent, a microbial water purifying agent and an enzyme preparation, wherein the flocculation water purifying agent is prepared from polyaluminum chloride, polyacrylamide, ferrous sulfate and aluminum sulfate; the microbial water purifying agent is prepared from nitrobacterium powder, paracoccus denitrificans powder, thiobacterium powder, aniline degrading bacteria powder and flocculating bacteria powder; the enzyme preparation is prepared from pectinase, cellulase, oxidoreductase, lysozyme and alkaline proteinase. The water purifying agent and the method have the beneficial effects that by adopting the water purifying agent for wastewater treatment, disclosed by the invention, the water purifying effect is good, the water purifying speed is high, the safety is high, and no secondary pollution is caused; materials with adsorption capacity are used as raw materials and are assisted with microbes, so as to treat the wastewater, so that the range of use is wide, the transparency of treated water is extremely high, and recycling can be achieved.