The invention belongs to the technical field of heavy 
metal wastewater treatment, and in particular relates to 
cyanuric acid-based heavy 
metal chelating flocculant and a preparation method thereof. In the method, 
cyanuric acid is adopted as a basic framework; and 
polyamine is connected to a molecule through 
epoxy chloropropane, and reacts with 
carbon disulfide in an alkaline condition to prepare the heavy 
metal chelating flocculant of which the molecule contains a plurality of branches and a plurality of dithio 
formate functional groups. The method overcomes the defects that the conventional monofunctional flocculant has small flocculating body, and poor 
precipitation performance, and when polymeric chelant chelates 
heavy metals, steric clash is great, and the residual heavy metal 
ion concentration is difficult to meet the standard and the like. The flocculant has the advantages of simple preparation process, mild condition, easy operation and control, high yield, high 
raw material utilization, less three waste 
discharge and 
environmental protection of technical process, convenient popularization and industrialization realization and suitability for treatment of various types of heavy metal 
wastewater, such as 
smelting wastewater, 
electroplating wastewater, nonferrous metals 
processing wastewater, mining and beneficiating wastewater, 
printed circuit board wastewater, battery plants and the like.