The present invention refers to a flame retardant comprising a complex formed by phosphine oxide and transition metal salt, wherein has good flame retardant property. The present invention also refers to a composite flame retardant and flame retardant antistatic composition, wherein composite flame retardant comprise the flame retardant and the inorganic flame retardant component as described above, which has an enhanced flame retardant effect; said flame retardant antistatic composition, comprising above described flame retardant or composite flame retardant and carbon nanofiber antistatic agent, wherein carbon nanofiber antistatic agent could have interaction with flame retardant, effectively reducing the amount of flame retardant, and the combination with the flame retardant without the adverse effect of each other which result in negative performance of each other, does not influence the subsequent foaming process and the foam structure and physical properties. The present invention also further refers to a flame resistant method, which adds the abovementioned flame retardant, composite flame retardant or flame retardant antistatic composition into the material, so that said material has flame retardance or flame retardance and antistatic, and has excellent mechanical properties.