Abstract: With the improvement of people’s living standards, a large number of petroleum products, daily necessities and decorations that can produce volatile organic compounds are used in decoration, which seriously affects the indoor air quality. Interior decoration materials have become a research hotspot in recent years. The purpose of this paper is to develop a kind of interior wall material with good indoor formaldehyde removal effect, easily using, and low cost. In this paper, combining different heat treatment temperatures of the glaze layer, tourmaline/diatomite-based interior wall tiles were prepared by ultrafine grinding, solid sintering, and low temperature calcination. The glaze layer under different heat treatment temperatures was characterized by thermogravimetric-differential thermal analysis, X-ray diffraction, and scanning electron microscope. The influences of heat treatment temperature on the microscopic morphology and structure of the glaze layer were analyzed. Taking formaldehyde as the target degradation product, the effects of tourmaline/diatomite-based interior wall tiles on the removal of formaldehyde under different heat treatment temperatures of the glaze layer were investigated. The results showed that with the increase in heat treatment temperature, the original pores of diatomite decreased, the specific surface area decreased, and the structure of tourmaline changed. At 850°C, the surface structure of the material was slightly damaged, the strength was increased, and the removal effect of formaldehyde was better. In a 1 m³ environmental chamber, the formaldehyde removal rate reached 73.6% in 300 min. When the temperature was increased to 950°C and above, diatomite and the structure of tourmaline were destroyed, and the ability of the material to adsorb and degrade formaldehyde decreased.