I want to know if there's a difference between getting personal loan from a finance company or a bank, considering the drop of credit score/grade (assume all other aspects are exactly the same)? I've heard from someone that it's better to get loan from a bank instead of a finance company to keep higher credit score/grade. Is it true?
It should not really matter who you go to purely in terms of credit score. Generally if you have a higher credit score you may get better loan terms from a bank, where a finance company will often be less discerning, but charge more.
Your credit report only really cares about the number of inquiries as well as the average age of credit in this situation. The loan source doesn't matter.
Please note applying at multiple banks should be fine if you want to shop around, a whole bunch of inquiries for loans of similar terms should not hurt your score significantly more than a single one. As long as you do them close together (all within a couple of weeks.)
My advice is to shop around both banks and finance companies and find out the best terms you can get. As long as you apply to them all and decide which you want to go with within a couple of weeks this should not impact your score significantly.
Note some free credit monitoring apps will incorrectly say each inquiry will reduce your score even if close together. And will not correctly fold together similar ones in a close time period, making your score appear lower than it is.
Each time you ask a bank or financial institution for a loan, they do a hard pull on your credit rating. You will be signalling to lenders that you're shopping for money. If you visit a mortgage broker he does a single hard pull on your credit score and offers your loan query to a dozen or more lenders, some of which you may not have even heard of.