I think it is not only his innate talent but also his hard working made him so successful.

问题描述:

I think it is not only his innate talent but also his hard working made him so successful.
这句话的语法正确吗?

不对,你用了强调句,后面要有that:
it is not only his talent but also his hard working that make him succeed.而且强调的部分要和后面的时态保持一致.