Xinjiang's education bureau said that the policy will be implemented in September, China Education Daily, a newspaper affiliated with Ministry of Education, reported on Friday.
Chinese Law on Standard Spoken and Written Chinese Language states that Putonghua is the standard spoken and written Chinese language.
The report said that all 2.94 million students in the nine-year free education period - primary and middle school - will receive Putonghua education.
Xinjiang is heavily populated by Uygur ethnic minority people. The regional government has been providing bilingual education to help spread Putonghua, the Xinhua News Agency reported in 2015.
In 2017, Putonghua was taught to 1.88 million students in the free education period, an increase of 1.05 million from the previous year, the newspaper said.
However, spreading Putonghua in some ethnic minority regions is challenging because of the lack of qualified teachers, Xiong Kunxin, a professor at Tibet University, told the Global Times previously.
China's education authorities released a plan in December 2017 to send more than 10,000 experienced teachers to Xinjiang as well as Southwest China's Tibet Autonomous Region, to guide and train local teachers and to help improve the quality of local education.
According to a development plan released by the Xinjiang education bureau in 2017, more than 98 percent of children will have access to three years of free preschool education.
By 2020, students from ethnic minority groups in this region will have a basic command of standard spoken and written Putonghua, the development plan said.