The invention relates to the technical field of production of thermoplastic elastomer materials, and discloses a synergistic halogen-free flame retardant and applications thereof, and an EPDM/PP thermoplastic elastomer, a preparation method and applications thereof, wherein the synergistic halogen-free flame retardant contains a nitrogen-phosphorus flame retardant and a CeMnO3 perovskite type composite oxide according to a weight ratio of (10-300):1. According to the present invention, the synergistic halogen-free flame retardant has good flame retardant performance, and the obtained halogen-free flame retardant TPV material has high tensile strength.