Can you clarify if you are looking to claim or get a business listed on Baidu Maps USA or Baidu Maps China? These are two separate situations.
If you are trying to get listed on or claim a listing on Baidu Maps USA you can use YEXT for this. Or if you do not want to use YEXT, I was able to find this contact form where I recommend reaching out to them directly and seeing your options.
If you are trying to get listed on Baidu Maps in China, then I believe you need to contact Baidu Maps China directly. (note this page is in Chinese). This is ONLY for businesses located in mainland China.
New advertising option:
A review of your product or service posted by a Sterling Sky employee. This will also be shared on the Sterling Sky & LSF Twitter accounts, our Facebook group, LinkedIn, and both newsletters.