Thanks for you reply, but when i co-simulation the generated fmu with simulink, it comes out with this error:

Error in supplied FMU: An error occurred in function 'fmi2DoStep' for block 'test/FMU' during simulation.

here is the info :

e:/OpenModelica1.12.0-64bit//share/omc/scripts/Compile.bat conditioning_circuit msvc10 mingw64 parallel 4 0
PATH = "e:\OpenModelica1.12.0-64bit\tools\msys\mingw64\bin;e:\OpenModelica1.12.0-64bit\tools\msys\mingw64\bin\..\..\usr\bin;"
Setting environment for using Microsoft Visual Studio 2010 x86 tools.

It seems to use 32bit compiler

actually i want to compile fmu with msvc10 64bit,and i will integrate this fmu to 64bit Simulink(with msvc10). But it failed, is it same to compile with gcc.?

Have you ever solved this problem? I also need to export modelica model to fmu on openModelica with 64 bit compiler