1.到opencv官網https://opencv.org/releases.html下載需要的opencn安裝包，如opencv-3.4.2，解壓
unzip opencv-3.4.2.zip
2.進入該文件夾
cd opencv-3.4.2
3.建立文件夾release
mkdir release
4.安裝依賴
sudo apt-get install build-essential cmake libgtk2.0-dev pkg-config python-dev python-numpy libavcodec-dev libavformat-dev libswscale-dev
5.進入release並編譯
cd release
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local ..
6.安裝
sudo make install