Douyin is a short video sharing platform and does not provide direct investment merchant functions. However, as an investment merchant, you can consider the following ways to cooperate with Douyin or gain business opportunities from it:

1. Advertising cooperation: As an investment merchant, you can contact Douyin's advertising team and cooperate with them to carry out brand advertising, and attract more users' attention and purchase intention by displaying your products or services on Douyin.

2. Cooperative marketing: Cooperate with influential Douyin creators or KOLs (key opinion leaders) who attract users' attention by posting promotional content on Douyin and can promote and recommend on behalf of your brand.

3. E-commerce live broadcast: There are many well-known anchors and influencers on Douyin, who recommend products to their fans and sell them through live broadcasts. You can cooperate with these anchors to show your products or services to more users through live broadcasts.

4. Open platform cooperation: Douyin has an open platform, which provides some APIs and tools to developers and merchants. You can explore the cooperation opportunities of Douyin's open platform and cooperate with Douyin in technology or services.

Please note that investment or cooperation with Douyin requires consultation and negotiation with Douyin. The specific cooperation methods and conditions should be communicated and confirmed with the Douyin platform. You can obtain more detailed cooperation information and processes through the Douyin official website or contact Douyin's business cooperation team.