The invention belongs to a multilevel 
processing method of waste water and a 
processing system thereof, and in particular discloses a 
processing method and a processing 
system for acidic waste water containing 
heavy metals. The invention comprises the following steps of: mixing carbon 
powder and 
scrap iron, adding 
modified zeolite, and placing the mixture into an inner 
electrolytic cell; conveying preprocessed waste water into the inner 
electrolytic cell, and reacting for 10 to 30 minutes under 
aeration condition; enabling outlet water to enter an electrochemical reaction 
cell directly, wherein the space between polar plates in the 
cell is from 0.6 to 1.4 cm, and reacting for 5 seconds to 5 minutes; and precipitating the outlet water, and separating 
solid from liquid. The processing 
system comprises a regulation 
cell, the inner 
electrolytic cell, the electrochemical reaction cell, a precipitating cell and a filtering cell which are sequentially connected, wherein the inner electrolytic cell is internally provided with a reaction 
bed, filter materials consisting of 
zeolite, carbon 
powder and 
scrap iron are filled in the reaction 
bed, an electrochemical reactor is installed in the electrochemical reaction cell, and a 
surface film filter is arranged in the filtering cell. The processing method has the advantages of wide application range, stable operation, good processing effect, low 
processing cost, environment protection, no 
pollution, and the like.