The invention discloses an angle steel tower material steal preventing device. The angle steel tower material steal preventing device comprises a sleeve, and a fixed lug arranged at the upper end of the sleeve; the sleeve is a hollow cylindrical structure; the fixed lug is fixedly connected to the upper end of the sleeve; a U-shaped groove is formed in the upper end surface of the fixed lug; two symmetric clamping grooves are formed in the lower end surface of the sleeve; the clamping grooves are symmetrically positioned on two sides of the groove; the sleeve includes an outer pipe manufactured by concrete, and a reinforcement net layer arranged on the inner side of the outer pipe; an outer-layer glass fiber cloth layer is arranged on the inner side of the reinforcement net layer; an inner pipe manufactured by the concrete is arranged on the inner side of the outer-layer glass fiber cloth layer; and an inner-layer glass fiber cloth layer is arranged on the inner side of the inner pipe. The angle steel tower material steal preventing device can achieve excellent cutting and steal preventing effects through the sleeve with multi-layer structure.