Apparently, there are at least some legislative issues/voids (without even talking about enforcement), at least from the Western perspective. The OCHR Committee (on the Elimination of Racial Discrimination) co-rapporteur for China, Nicolás Marugán said in a 2018 conference that
The domestic legislation did not define racial discrimination in line with the Convention, remarked Mr. Marugán, and while ethnic discrimination was prohibited, the law was silent on the type of action or behaviour that constituted discrimination. Would China enact laws that would prohibit discrimination on all grounds, including on the grounds of descent and national origin, and draft an anti-discrimination law? Was there any data available on discrimination against ethnic minorities in the areas of employment, education, housing, health care, and access to social services and economic opportunities?
A Chinese delegate responded to that:
On the definition of racial discrimination and the anti-racial discrimination law, a delegate said that China had a comprehensive legal system underpinned by the Constitution to promote ethnic equality and prohibit racial discrimination in line with the spirit of the Convention, whose provisions had been fully implemented under a range of laws, including the Law on Regional National Autonomy, Electoral Law, Labour Law, Public Security Administration Punishments Law, and others. Though there was no definition of “racial discrimination”, the understanding and interpretation of “racial discrimination” by the legislature, judicial authority and the administrative departments was consistent with the Convention, said the delegate.
(I've omitted the part(s) about the anti-terror laws in the conference, which the committee co-rapporteurs also expressed concerned were being used in a discriminatory manner, e.g. against Uyghurs, which China obviously also denied is the case.)