Anti-theft well head device

The utility model discloses an anti-theft well head device and relates to the field of abandoned well plugging processing devices. A casing flange (17) is arranged at the lower end of a wellhead four-way (14), a steel ring (15) is arranged between the wellhead four-way (14) and the casing flange (17), one end of an anti-theft bolt (16) passes through an anti-theft cover(1) and is connected with the wellhead four-way (14) in a rotating mode, the wellhead four-way (14) is connected with the casing flange (17) through a bolt (18) and fixed by a nut (19), a protecting sleeve (20) is arranged on the bolt (18), a casing pipe (21) is arranged on the casing flange (17), oil pipes (22) are coaxially arranged in the casing pipe (21), and the upper ends of the oil pipes (22) are connected with the wellhead four-way(14) in a rotating mode. The anti-theft well mouth device is simple in structure, small in size, low in cost, complete in functions, reliable in performance, high in anti-theft grade, convenient to monitor, re