An anti-pierce isolation fence comprises stand columns.A fence body is arranged between the stand columns.The fence body comprises an upper beam, a lower beam and vertical rods installed between the upper beam and the lower beam.Connecting pieces are installed on the inner sides of the stand columns and arranged in disengagement holes and connecting groove holes.The disengagement holes are connected with the connecting groove holes.The connecting groove holes are located in the inner sides of the disengagement holes.The upper beam of the fence body in the anti-pierce isolation fence is connected with the connecting pieces through connecting bolts, when the fence is hit at a small angle, the upper beam can be disengaged and disconnected from the stand columns, so the far end of the upper beam can lose support, and the near end of the upper beam is prevented from piercing through a windscreen.