I am trying to read the Vulgate but I have now met a serious problem. The
text is not printed with macrons as the following link:
http://www.drbo.org/lvb/chapter/47001.htm
Since there are so many biographical and geographical names in the Bible, how
can I decide the word stress without the help of the macrons?

no, you can't. but you can find the correspondingsin ancient Greek to figure out whetherthere is a macron or not

But the OT was written in Hebrew, not in Greek.

but you're asking for "Latin pronunciation"Which is transliterated directly from Septuagint

cant see why this is a serious problem -- the vulgatewas written in 382; by then vowel length would ceaseto be phonemic

If the vowel length ceased to to phonemic, how todetermine what syllable the stress falls on

Even the vowel length would cease to be phonemicthe stress caused by vowel length remains