I still don't know why this problem happened, but I solved it :)
My model is test1.slx，so the Embeded Coder will build the directory C:\Users\Liu\Documents\MATLAB\test1_ticcs to save the generated C and other files.
I copied "rts2800_fpu32.lib" to the directory，and the Embeded Coder will generated test1.out correctly! (I still fighting for the problems in the next steps)
To make this action automatically, I set a Pre-build in the xmakefilesetup() windows，which is:
Pre-build tool: C:\Windows\System32\xcopy
Arguments: C:\ti\ccsv5\tools\compiler\c2000_6.1.3\lib\rts2800_fpu32.lib . /Y
The reason why use xcopy instead of copy: "copy" is not a Windows Command File, MATLAB can't call it.