The invention discloses a belt breakage detecting device. A belt is driven by a driving device. The device provided by the invention comprises a controlling device, a guiding device, a floating type machine rack capable of moving along the guiding device in a reciprocating manner, and a belt compressing device and a broken belt triggering device arranged on the floating machine rack; the controlling device is connected with the broken belt triggering device and is provided with an interface connected with the belt driving device; a contact part contacting with the belt is arranged on the belt pressing device and the broken belt triggering device respectively; the broken belt triggering device is used for sending a belt breakage signal to the controlling device according to the contacting pressure change between the contact part and the belt under test. The belt breakage detecting device provided by the invention has a simple and artistic structure. The invention further provides a shear fork lifting device.