悉尼大学毕业有honour学位与没有honour学位想申请美国读硕士有区别吗

depends on the University at US and whether you are applying for Master by coursework or master by research. Normally, in the case of Australia, if you just have a UG without honours, you may be able to study Master by coursework and most probably NOT Master by research. This could be similar in the US ...