The invention relates to a triazine type hyperbranched polyurea charring agent and a preparing method thereof. In a solvent, -NCO groups of isocyanate and -NH2 in melamine are used for being reacted with each other, and the charring agent with the hyperbranched structure is generated, wherein triazine rings and a plurality of benzene rings are contained in the molecular structure, good charging performance is achieved, good hydrophobicity is shown, the contact angle reaches 90 degrees, and the compatibility with high polymer matrixes can be obviously improved. The charring agent has very good thermal stability and meets the processing requirement of high polymers, and the phenomenon that materials are degraded in the processing process, and consequently the flame retardance of the materials is lowered is avoided; when the charring agent and acid-source ammonium polyphosphate are added into polypropylene at 1:2, the limit oxygen index of a polypropylene composite reaches up to 32%, and a sample strip with the thickness of 1.6 mm can pass the UL-94 perpendicular combustion V-0 grade.