Anti-dismounting and anti-theft bolt

The invention discloses an anti-dismounting and anti-theft bolt. The anti-dismounting and anti-theft bolt comprises a bolt head, a flange plate, a polish rod and a screw rod, wherein the flange plate is located between the bolt head and the polish rod; the screw rod is provided with an axial pin groove; the lower end of the polish rod is provided with an axial wedge-shaped pin groove the same as the axial pin groove. The anti-dismounting and anti-theft bolt has the advantages that the polish rod is provided with the axial wedge-shaped pin groove communicated with the axial pin groove in the screw rod, the depth of the axial wedge-shaped pin groove is gradually decreased in the direction from the screw rod to the flange plate, and therefore an anti-theft pin not only can act between the screw rod and a nut, but also can act between the polish rod and a connected part, and the anti-dismounting and anti-theft functions are achieved. The bolt head is changed to be in a hemispherical shape and can be effectively prevented from being unscrewed by lawbreakers through tools like spanners compared with ordinary bolt heads; meanwhile, the diameter of the bolt head is larger than that of the flange plate, so that the effect of hiding all the components below the bolt head can be achieved effectively, and the anti-theft performance is better.