A dial wheel device has a controller. The controller has a positioning rod. An adjuster, a dial wheel module, a seat and a restoring element are mounted on the positioning rod. The dial wheel module has multiple dial wheel assemblies. Each dial wheel assembly has an outer ring and an inner ring. In the code-unchanged state, the outer ring and the inner ring are coactive. In the code-changing state, the adjuster is rotated and the guide element forms a lateral displacement to push the inner ring, and the outer ring and the inner ring are non-coactive. The outer ring is turned to reset the code. When the code-changing state is finished, the adjuster is rotated again and the outer ring and the inner ring are coactive again. Therefore, the components of the code-changeable assembly are simplified and the dial wheel device is easy to assemble and operate.