A multidirectional magnetized permanent magnetic adsorption device (PMAD) for wall-climbing robots is proposed. The novel PMAD can significantly increase the adsorption force under the same mass. Firstly, the magnetic circuit of the novel PMAD was optimized based on the design theory proposed in this paper. The novel PMAD contains multiple closely arranged permanent magnets with different magnetizing directions. The magnets can be divided into several component units by the arrangement regulation of the magnetizing directions. In every component unit, the magnetizing directions distribute along a semi-circle. Secondly, Finite element analysis software Ansys Workbench was used for parameterized modeling, structural characteristic analysis, magnetic circuit simulation, adsorption force calculation and parameter optimization of the novel PMAD. Then, The novel and the Halbach type of PMADs with the same material and volume were trial-produced. The adsorption force was measured under different air gap thicknesses. The experimental results proved that the adsorption force of the novel PMAD doubled averagely compared with the Halbach type of PMAD under the same mass, and the largest amplification was 2.3 times. Finally, the novel PMADs were applied in a wall-climbing robot for ultrasonic testing, and provide steady and reliable adsorption.