Why does a visa officer refuse to sign a B2 visa just on the basis of his passport?

In this case, there are usually several possibilities:

First: there is a credit problem and the embassy has a bad record. In this case, it is useless for you to apply again. As long as you apply, you will be refused a visa. In fact, there is no way.

Second: Form 160 is wrong or incomplete. Generally, this form will be filled out before applying for an American visa, which is also the place where visa officers first get to know you. If there is something wrong with your form, if you fill it out badly, your score will be very low. Basically don't ask too many questions. Just look at the passport and refuse the visa directly.

So see if your materials meet the requirements of American visa, or where they can be improved. The rest is to see what your reason for refusing is. The refusal letter is marked, find out the reason, check the leakage and fill the vacancy, and maybe the pass rate will be higher when signing again. If it is not convenient to talk about it here, you can take your materials to the website for consultation and see if there are any problems.