The invention provides a bidirectional tri-path turn-on high-voltage ESD (Electro-Static Discharge) protective device which can be used in an on-chip IC (Integrated Circuit) high-voltage ESD protective circuit. The bidirectional tri-path turn-on high-voltage ESD protective device comprises a P minus substrate, an N plus buried layer, a left N-type epitaxy, a right N-type epitaxy, a drifting area, a high-voltage P trap, a drain region, a source region, a polysilicon gate, a positive pole contact area and a negative pole contact area, wherein the drifting area, the high-voltage P trap, the drain region, the source region and the polysilicon gate form an NLDMOS (laterally diffused metal oxide semiconductor) structure, and the positive pole contact area, the N plus buried layer, the high-voltage P trap and the source region form a positive SCR (semiconductor control rectifier)structure, so that two high-voltage ESD current discharge paths are formed to improve secondary striking current of the device and reduce the turn-on resistance and trigger voltage; and the negative pole contact area, the left N-type epitaxy, the high-voltage P trap, the N plus buried layer and the drain region form a reverse SCR structure to form a reverse high-voltage ESD current discharge path. The current paths of the two SCR structures are longer, so that the maintaining voltage of the device can be improved, bidirectional discharge of ESD current can be realized, and the device has bidirectional ESD protection function.