Thanks rjcox for replying,
At first, I thought this could be the manifest problem, So I asked the person to re-modified the program and re-built it with the manifest dll, but still I couldn't import or load the dll into my c# project and call one of the function in the dll. I tested the program itself and it works fine but when I want imported it into my c# project and it failed because of Runtime Error R6034, An application has made an attempt to load the C runtime lib incorrectly