第一步:

打开QtCreator，点击File，选择New File or Project，选择None-Qt Project,选择Plain C++ Project，点击choose ，然后基本都选默认的就行。项目建立完成后就会看到一个*.pro文件，修改.pro文件中的内容，如下：

TEMPLATE = app
CONFIG += console c++11
CONFIG -= app_bundle
CONFIG -= qt

SOURCES += \\
        main.cpp

第二步:

在“.pro”文件中配置OpenCV的库文件，配置清单如下：

INCLUDEPATH += /usr/local/opencv3.4.2/include \\
                /usr/local/opencv3.4.2/include/opencv \\
                /usr/local/opencv3.4.2/include/opencv2

LIBS += /usr/local/opencv3.4.2/lib/libopencv_aruco.so \\
/usr/local/opencv3.4.2/lib/libopencv_bgsegm.so \\
/usr/local/opencv3.4.2/lib/libopencv_bioinspired.so \\
/usr/local/opencv3.4.2/lib/libopencv_calib3d.so \\
/usr/local/opencv3.4.2/lib/libopencv_ccalib.so \\
/usr/local/opencv3.4.2/lib/libopencv_core.so \\
/usr/local/opencv3.4.2/lib/libopencv_datasets.so \\
/usr/local/opencv3.4.2/lib/libopencv_dnn_objdetect.so \\
/usr/local/opencv3.4.2/lib/libopencv_dnn.so \\
/usr/local/opencv3.4.2/lib/libopencv_dpm.so \\
/usr/local/opencv3.4.2/lib/libopencv_face.so \\
/usr/local/opencv3.4.2/lib/libopencv_features2d.so \\
/usr/local/opencv3.4.2/lib/libopencv_flann.so \\
/usr/local/opencv3.4.2/lib/libopencv_freetype.so \\
/usr/local/opencv3.4.2/lib/libopencv_fuzzy.so \\
/usr/local/opencv3.4.2/lib/libopencv_hfs.so \\
/usr/local/opencv3.4.2/lib/libopencv_highgui.so \\
/usr/local/opencv3.4.2/lib/libopencv_imgcodecs.so \\
/usr/local/opencv3.4.2/lib/libopencv_img_hash.so \\
/usr/local/opencv3.4.2/lib/libopencv_imgproc.so \\
/usr/local/opencv3.4.2/lib/libopencv_line_descriptor.so \\
/usr/local/opencv3.4.2/lib/libopencv_ml.so \\
/usr/local/opencv3.4.2/lib/libopencv_objdetect.so \\
/usr/local/opencv3.4.2/lib/libopencv_optflow.so \\
/usr/local/opencv3.4.2/lib/libopencv_phase_unwrapping.so \\
/usr/local/opencv3.4.2/lib/libopencv_photo.so \\
/usr/local/opencv3.4.2/lib/libopencv_plot.so \\
/usr/local/opencv3.4.2/lib/libopencv_reg.so \\
/usr/local/opencv3.4.2/lib/libopencv_rgbd.so \\
/usr/local/opencv3.4.2/lib/libopencv_saliency.so \\
/usr/local/opencv3.4.2/lib/libopencv_sfm.so \\
/usr/local/opencv3.4.2/lib/libopencv_shape.so \\
/usr/local/opencv3.4.2/lib/libopencv_stereo.so \\
/usr/local/opencv3.4.2/lib/libopencv_stitching.so \\
/usr/local/opencv3.4.2/lib/libopencv_structured_light.so \\
/usr/local/opencv3.4.2/lib/libopencv_superres.so \\
/usr/local/opencv3.4.2/lib/libopencv_surface_matching.so \\
/usr/local/opencv3.4.2/lib/libopencv_text.so \\
/usr/local/opencv3.4.2/lib/libopencv_tracking.so \\
/usr/local/opencv3.4.2/lib/libopencv_videoio.so \\
/usr/local/opencv3.4.2/lib/libopencv_video.so \\
/usr/local/opencv3.4.2/lib/libopencv_videostab.so \\
/usr/local/opencv3.4.2/lib/libopencv_viz.so \\
/usr/local/opencv3.4.2/lib/libopencv_xfeatures2d.so \\
/usr/local/opencv3.4.2/lib/libopencv_ximgproc.so \\
/usr/local/opencv3.4.2/lib/libopencv_xobjdetect.so \\
/usr/local/opencv3.4.2/lib/libopencv_xphoto.so

第三步:

如果运行程序,提示error while loading shared libraries: libopencv_highgui.so.3.0: cannot open shared object file错误,在/etc/ld.so.conf.d目录中新建一个xxx.conf文件,如opencv.conf,并在其内容中写入刚才找到的库的路径：

/usr/local/lib
/usr/local/opencv3.4.2/lib

保存后执行：

$ sudo ldconfig