As a combination of highest harness, thermal conductivity, thermal shock resistance and high strength, diamond film has attracted a large number of researches. From the 20th century when diamond was prepared by chemical vapor deposition (CVD) at low pressure, the related deposition science and technology have rapidly developed. In this article, a review on techniques aims at producing diamond wafers useful for infrared windows will be presented, and special attention will be given to the recent progress made in China to produce high quality diamond wafers. Until now, Hot Filament CVD, Direct Current Plasma Assisted CVD, DC Arc Plasma Jet CVD and Microwave Plasma CVD have been still developing. On the basis of research on high quality diamond films with small size, in the early 21st century, several foreign developed countries have declared mastering the techniques to deposit high-quality diamond wafers with large area and the films have been used in high-tech areas, such as infrared optical window, et al. Hot Filament CVD, DC Arc Plasma Jet CVD and Direct Current Plasma Assisted CVD have been mastered in China because the diamond techniques have also been developed rapidly. Recently, a novel system of 915 MHz microwave plasma CVD developed successfully, which illustrates the technique for preparing high-quality diamond film in China has kept up with the advanced level abroad.