An optical fiber fusion splicer comprising a fusion splicing part, wherein the fusion splicing part can splice optical fibers, wherein the optical fiber fusion splicer further comprises: a first clamping part (3, 4) respectively provided on either side of the fusion splicing part, wherein the first clamping parts (3, 4) can clamp optical fibers and move in the lengthwise direction of the optical fibers; a cutting part (5, 6) respectively provided on either side of the fusion splicing part, wherein the cutting parts (5, 6) is arranged between the first clamping parts (3, 4) and the fusion splicing part and provided with cutting blades suitable to cut optical fibers and second clamping parts; the second clamping parts are arranged between the cutting blades and the fusion splicing part; wherein the cutting parts (5, 6) can move, so that the cutting parts (5,6) withdraw from positions between the first clamping parts (3, 4) and the fusion splicing part, characterized in that the optical fiber fusion splicer comprising a working platform and the fusion splicing part provided on the working platform, and the second clamping part of each of the cutting parts (5, 6) comprises a second fixed part and a second moving part, wherein each of the cutting parts (5, 6) is provided with a driving part, which drives the cutting blade to move towards or away from the second fixed part; the cutting blade is connected to the second moving part via an elastic part; when the elastic part is in an extended state, the second moving part is closer to the position where the optical fiber is located than the cutting blade; and when the elastic part is compressed and contracted as the second moving part is in contact with the second fixed part, the cutting blade can continue to move towards the position where the optical fiber is located so as to contact the optical fiber. a first clamping part (3, 4) respectively provided on either side of the fusion splicing part, wherein the first clamping parts (3, 4) can clamp optical fibers and move in the lengthwise direction of the optical fibers; a cutting part (5, 6) respectively provided on either side of the fusion splicing part, wherein the cutting parts (5, 6) is arranged between the first clamping parts (3, 4) and the fusion splicing part and provided with cutting blades suitable to cut optical fibers and second clamping parts; the second clamping parts are arranged between the cutting blades and the fusion splicing part; wherein the cutting parts (5, 6) can move, so that the cutting parts (5,6) withdraw from positions between the first clamping parts (3, 4) and the fusion splicing part, characterized in that the optical fiber fusion splicer comprising a working platform and the fusion splicing part provided on the working platform, and the second clamping part of each of the cutting parts (5, 6) comprises a second fixed part and a second moving part, wherein each of the cutting parts (5, 6) is provided with a driving part, which drives the cutting blade to move towards or away from the second fixed part; the cutting blade is connected to the second moving part via an elastic part; when the elastic part is in an extended state, the second moving part is closer to the position where the optical fiber is located than the cutting blade; and when the elastic part is compressed and contracted as the second moving part is in contact with the second fixed part, the cutting blade can continue to move towards the position where the optical fiber is located so as to contact the optical fiber.