Not true.

Unless you explicitly renounce Chinese citizenship, and the government is unaware you have taken out another passport, you remain a Chinese citien :

https://expatriates.stackexchange.com/questions/4455/what-happens-when-chinese-acquire-foreign-citizenship

specificaly :

"if a person has Chinese nationality and foreign nationality at the same time, China only recognizes this person's Chinese nationality, and does not recognize the person's foreign nationality"