After analyzing the cause of the phenomenon of heaping thinner and uneven thickness in the wall thickness when coaxial inside-beam powder feeding laser cladding is used in the accumulation of variable diameter solid, we propose to control the amount of defocus layer by layer to compensate the pool of liquid metal loss and to keep the cladding layer width. Through a large number of experimental data, we demonstrate the relationship between the variation of defocus amount and slope of the variable diameter solid, and thus in the accumulation process the control of defocus amount can be changed in real time according to the variable rotary slope. By real-time controlling the amount of defocus, and correspondingly controlling the amount of the powder feeding and laser power, a few typical variable diameter rotating solid with good surface quality and uniform thickness are got. The molded parts show fine microstructure and excellent mechanical properties. The hardness of the molded parts is measured, the overall hardness is higher than that of the substrate and evenly distributed.