The utility model relates to a displacement detection alarming device, which comprises a touch-pressure switch, a height adjusting device, an alarming device, a holding device and a power supply, wherein, the alarming device is connected with the power supply through the touch-pressure switch; and the touch-pressure switch and the holding device are fixed on the height adjusting device. The detection alarming device has a wide application range, and can be widely used in production and life, particularly for correcting sitting posture of students in middle and primary schools and to prevent myopia; and the detection alarming device is formed through plastic injection moulding, and has the advantages of simple structure, low cost and obvious economic and social benefits.