The utility model provides an anti-theft bolt assembly and a spanner. The anti-theft bolt assembly comprises a sleeve and a bolt, wherein one end of the sleeve is an open end; a through hole is formed in the other end of the sleeve; the radius of the through hole is smaller than the radius of the head of the bolt, and greater than or equal to the radius of the screw of the bolt; the screw is arranged on one side of the head of the bolt, and a stop rod is eccentrically arranged on the other side of the head; the head of the bolt is nested into the sleeve and the screw of the bolt is capable of extending through the through hole and out of the sleeve; the spanner comprises an inserting rod, wherein a groove matched with the head of the bolt and the stop rod is formed in one end of the inserting rod; one end of the spanner can be inserted into the open end of the sleeve and is in corresponding plug-in connection with the head of the bolt. The anti-theft bolt assembly needs to be matched with the spanner in use and cannot be opened without the spanner, and therefore, a manhead can be effectively prevented from being opened maliciously and reduction gear oil can be prevented from being stolen; as a result, the case that a pumping unit is damaged and the production of an oil well has to be stopped is avoided and normal operation of the pumping unit is guaranteed.