A melamine derivative of Formula I and its preparing method are provided:wherein,R is the same with or different from each other and has the formula ofR1 and R2 are independently selected from a group consisting of H, a halogen, a substituted or unsubstituted C1-C15 alkyl, a substituted or unsubstituted C1-C15 alkoxy, a substituted or unsubstituted C3-C15 cycloalkyl, a substituted or unsubstituted C6-C20 aryl, a substituted or unsubstituted C6-C20 aryloxy, a substituted or unsubstituted C1-C15 unsaturated hydrocarbyl, a naphthol group, a phenanthrenol group, and a dicyclopentadiene group, with a proviso that R2 is not H andm is 1 or 2.
