Seeing the recruitment board in front of the factory, I asked the security guard if he was hiring. If he is hiring, will the security guard take me there?

Since it is posted at the door, of course, you can only enter through the security guard. Ask the security guard if he still needs anyone, and then the security guard will call the personnel department. After the personnel department confirms the interview time, you go to the security guard to register the information. If you don't use it, he will give you a temporary access card. Ask the security guard how to get there, and he will tell you how to get there and where to interview. You can return the card to the security guard after the interview.