Does the accountant has the right to visit the construction site?

More detail is needed for your question.
Public (government financed) or private site?
Who is accountant employed by?
What is the purpose of the visit?
If it is public and request is made through the proper govt office, probably yes, but contractor would have the right to object, owner (govt) would have final say.
If you represent a competing contractor, on a public site you could request records under Public Info Act, but records describing trade secrets, etc. probably would not be released

I am working as an accountant in a private construction company in saudi arabia.For to update the accounts information I need to visit the construction site.I want to know whether the accounting policies allowing to visit the site.

I spent 4 years in KOSA, my wife spent 11. You must have permission from the police in the area where you are leaving from, and the area where you are going to, before you travel. Shiria is very strict.

I am working as an accountant in a private construction company in saudi arabia.For to update the accounts information I need to visit the construction site.I want to know whether the accounting policies allowing to visit the site.

My site manager saying that the accountant don't have the right to visit the construction site(any working site) for my job purpose.Please give me an answer for the same.

Sorry, all my experience is in U.S.
You still don't say if it is public or privately financed work. I think that could make a diff.
In the U.S. whether public or private work, the contractor's accountant would have the right to visit that same contractor's work site, with his supervisors approval. To make it flow smoother, an executive of your company, should make a ruling if the field supervisor has a different opinion.

Your employer can choose whether, to get a Travel Letter for you. Without one do not travel. In KOSA the prisoners in jail are not given food. If someone from outside doesn't bring you food, you starve... it's the will of Allah. Restrictions on travel depend on the color of your Igama, and you need a Travel Letter with it for all stops and checkpoints.