The invention discloses a shear gauge stop head contact detection device and a shear gauge. The shear gauge stop head contact detection device comprises a detection plate (16) and a travel switch (14); the detection plate (16) comprises a strip-shaped contact section (116); the contact section (116) is arranged slantways relative to a vertical plane; the detection plate (16) is connected with a detection plate rotating shaft (113); and when the detection plate (16) rotates by taking the detection plate rotating shaft (113) as a shaft and the contact section (116) is positioned in the vertical plane, the detection plate (16) can trigger the travel switch (14). The shear gauge stop head contact detection device is arranged on a stop head of the shear gauge, and is used for detecting whether the head of a steel plate is completely fit with the stop head of the shear gauge or not when the shear gauge performs specified length shearing. Mainly through a mechanical mechanism and when the steel plate clings to the stop head of the shear gauge, the detection unit triggers the travel switch to send out a signal, so that the detection aim is fulfilled.