The invention relates to the technical field of sensors and provides an attitude detection sensor. The sensor comprises a casing, a signal unit and a control unit, wherein a cavity is formed in the casing and filled with liquid metal and a buffer solution, and the density of the buffer solution is smaller than that of the liquid metal; the signal unit is inserted into the casing and used for generating different electrical signals through contact of the liquid metal with different parts of the signal unit when the attitude of the casing changes; the control unit is electrically connected withthe signal unit. The attitude detection sensor is simple in structure and convenient to mount; when the attitude of a to-be-detected device changes, the liquid level of the liquid metal in the casingchanges correspondingly, and the contact part of the liquid metal and the signal unit also changes, so that electrical signals generated by the signal unit change; the control unit can calculate the change condition of the attitude of the to-be-detected device according to the electric signals fed back by the signal unit, the to-be-detected device can be timely adjusted accordingly, and safe and reliable operation of the to-be-detected device is guaranteed.