Hi @shenxiaoyin, welcome to the Forum!
If your organization is ready to apply for membership you may complete a membership application here.
Within 10 business days, we will review your application and reply either to ask any questions or to provide your first year’s membership order (invoice). You will have a few options to pay this, including credit/debit card, wire transfer, or check (for an additional fee).
Once you’ve completed payment we will issue you your DOI prefix and you can begin registering DOIs.
My colleague @robbykharosalien has written more extensively about the application process and each of its steps over here.
Please let me know if you have any other questions.