问个英文问题

如果单项选择，应该是：my opinion is the same as his.
你如果google一下就会找到很多例句，例如：

My monthly salary is almost the same as his.

Even your voice sounds the same as his.

当然，the same with his的句型也不算错，多项选择时也可以入选。不过一般情况下，它的意思就不同了：
So I did the same with his profile.
因此，我对他的文档作了同样的事。

my opinion is the same as him
be the same as 和……一样，这是固定短语

my opinion is the same as his

my opinion is the same with his
my opinion is the same as his

the two above is OK

my opinion is the same to his.