The invention belongs to the technical field of flame retardants, and particularly relates to a reactive type halogen-free flame-retardant plasticizer, the structural formula of which is shown in the specification, wherein R1 is H or any one C1-C6 straight-chain alkyl or phenyl; R2 is H or any one C1-C6 straight-chain alkyl; R3 to R12 are H, any one C1-C6 straight-chain alkyl or phenyl. The molecular structure of the flame-retardant plasticizer simultaneously contains diphenyl phosphate, N and a substituted acrylic acid group, so that the reactive type halogen-free flame-retardant plasticize integrates the flame retardance and plasticization functions, and is good in flame-retardant property and environment-friendly.