I slove it,
you can see libtorch-demo/example-app at main · carlsummer/libtorch-demo · GitHub 26,
set(CMAKE_BUILD_TYPE “Release”)
-DCMAKE_PREFIX_PATH=path\to\opencv\build\x64\vc14\lib;path\to\libtorch -DCMAKE_BUILD_TYPE=Release -G"Visual Studio 14 Win64"