Does Fudan University need an undergraduate thesis for the cross-examination

No need.

Scientific research experience can only be submitted to the school as personal data during the second interview, and the school may add points as appropriate. The initial test is not directly related to the school. Moreover, since it is a master's degree rather than a master's degree, it does not value scientific research experience and belongs to a cross-major. I believe it won't have much impact. But as personal data, if the school allows, you can submit it for a try.