on the team 和 in the team，都对。

前者为美国英语；后者为英国英语。

用of the team 也有，但一般表示“部分与整体；成员与团队”关系。例如：

1. I was a part of the team and wanted to remain a part of the team. 

2. No member of the team was medically qualified and its methods were considered totally unscientific. 

3. A good crowd will be a definite advantage to me and the rest of the team. 

以上例句均来自《柯林斯词典》