The high-temperature chemical method of tungsten diiodide is legally produced by the reaction of elemental tungsten and elemental iodine at temperatures between 600 and 800°C: W+I₂→WI₂. Generally, the temperature selected for the reaction is 800°C, and tungsten diiodide is produced using the reaction of tungsten powder with iodine.

Tungsten diiodide (WI₂) has good stability at room temperature but readily reacts chemically at high temperatures and in the presence of oxygen. Tungsten diiodide is an inorganic compound with the following chemical properties.

There are three direct preparation methods for tungsten diiodide, which are obtained by high-temperature chemotaxis, halide exchange reaction, and reaction of tungsten hexacarbonyl with elemental iodine. Meanwhile, tungsten diiodide can also be obtained by indirect method.

Tungsten diiodide is a transition crystal. Transitional crystals are different from many substances in nature with regular geometrical shapes, such as ionic crystals, molecular crystals, atomic crystals, and metal crystals. The inter-particle role of the lattice junctions of the transitional crystals has changed, and the interactions between particles of the crystalline structure and the nature of the crystal between the different types of crystalline forms, which is difficult to be classified as any of the above-mentioned typical crystals, and there are a lot of actual crystals belonging to the transitional crystals.