Supposedly, it should be the China Consumers Association, and all consumers in China are members of this association. However, due to organizational reasons and strong pressure from interest groups, this organization has no rules and regulations on joining and withdrawing.
Therefore, the second best thing is that the largest association in China today is the China Disabled Persons' Federation. Yes, it is the Disabled Persons' Federation. If mental patients are included, the total population is close to 1 100 million.