The invention relates to a device and a method used for optical fiber splice tensile force testing. The device comprises a testing body and a balancing lever. The middle part of the testing body is provided with a guide rail, and the upper part of the testing body is provided with a clamp used for clamping a to-be-tested optical fiber splice. The balancing lever is slidably connected with the guide rail of the testing body, and one end of a to-be-tested optical fiber is connected with the middle part of the balancing lever by a connecting rod. The balancing lever comprises a horizontal rod, a fixing block connected with the middle part of the horizontal rod by a rotating shaft, a first weight in a threaded connection with one side of the horizontal rod, and a second weight slidably connected with the other side of the horizontal rod. The fixing block is slidably connected with the guide rail of the testing body. A testing method adopting the above mentioned device is used for the tensile force testing of the optical fiber splice by using a lever principle. Compared with the prior art, testing results acquired by the device and the method are accurate and reliable, and the whole device is stable and reliable, and repeatability is high.