A high-safety surge protective device comprising: a box, a first and a second electrode, an overvoltage protection component having a first and a second pin, the first pin connected to the first electrode, a release unit having a metal piece, wherein the metal piece is connected to the second electrode via a flexible conductor, wherein an end of the metal piece is soldered or brazed to the second pin, when the surge protective device is in a normal operating condition, wherein the release unit has a slide and a first spring, wherein the metal piece is mounted on the slide, wherein the first spring is arranged between the slide and a bracket on the box for driving the slide together with the metal piece to a first limit wall of the box and for separating the metal piece from the second pin, when a temperature at the solder or brazing between the second pin and the metal piece has reached a melting or fusion point of the solder or brazing, a turning block having an arc reflector plate, characterized in that the first spring is a compression spring, wherein a second end of the turning block is rotatably attached to a pin roll on said box, wherein a torsional spring is mounted on the turning block and connected with said pin roll for applying a torque on the turning block pushing a first end of turning block towards a second limit wall of said box, wherein the arc reflector plate is in contact with the metal piece as long as the surge protective device is in the normal operating condition, and wherein a spark chamber located between the arc reflector plate and the second end of the turning block covers the second pin when the metal piece is separated from the second pin. a box, a first and a second electrode, an overvoltage protection component having a first and a second pin, the first pin connected to the first electrode, a release unit having a metal piece, wherein the metal piece is connected to the second electrode via a flexible conductor, wherein an end of the metal piece is soldered or brazed to the second pin, when the surge protective device is in a normal operating condition, wherein the release unit has a slide and a first spring, wherein the metal piece is mounted on the slide, wherein the first spring is arranged between the slide and a bracket on the box for driving the slide together with the metal piece to a first limit wall of the box and for separating the metal piece from the second pin, when a temperature at the solder or brazing between the second pin and the metal piece has reached a melting or fusion point of the solder or brazing, a turning block having an arc reflector plate, characterized in that the first spring is a compression spring, wherein a second end of the turning block is rotatably attached to a pin roll on said box, wherein a torsional spring is mounted on the turning block and connected with said pin roll for applying a torque on the turning block pushing a first end of turning block towards a second limit wall of said box, wherein the arc reflector plate is in contact with the metal piece as long as the surge protective device is in the normal operating condition, and wherein a spark chamber located between the arc reflector plate and the second end of the turning block covers the second pin when the metal piece is separated from the second pin.