AssertionError: MMCV==1.7.1 is used but incompatible. Please install mmcv＞=2.0.0rc4, ＜2.1.0.

原因分析：是因为mmdet与mmcv-full版本不一致，查看版本对照表。

MMDetection3D version	MMDetection version	MMSegmentation version	MMCV、 version
master	mmdet>=2.24.0, <=3.0.0	mmseg>=0.20.0, <=1.0.0	mmcv-full>=1.5.2, <=1.7.0
v1.0.0rc4	mmdet>=2.24.0, <=3.0.0	mmseg>=0.20.0, <=1.0.0	mmcv-full>=1.5.2, <=1.7.0
v1.0.0rc3	mmdet>=2.24.0, <=3.0.0	mmseg>=0.20.0, <=1.0.0	mmcv-full>=1.4.8, <=1.6.0
v1.0.0rc2	mmdet>=2.24.0, <=3.0.0	mmseg>=0.20.0, <=1.0.0	mmcv-full>=1.4.8, <=1.6.0
v1.0.0rc1	mmdet>=2.19.0, <=3.0.0	mmseg>=0.20.0, <=1.0.0	mmcv-full>=1.4.8, <=1.5.0
v1.0.0rc0	mmdet>=2.19.0, <=3.0.0	mmseg>=0.20.0, <=1.0.0	mmcv-full>=1.3.17, <=1.5.0
0.18.1	mmdet>=2.19.0, <=3.0.0	mmseg>=0.20.0, <=1.0.0	mmcv-full>=1.3.17, <=1.5.0
0.18.0	mmdet>=2.19.0, <=3.0.0	mmseg>=0.20.0, <=1.0.0	mmcv-full>=1.3.17, <=1.5.0
0.17.3	mmdet>=2.14.0, <=3.0.0	mmseg>=0.14.1, <=1.0.0	mmcv-full>=1.3.8, <=1.4.0
0.17.2	mmdet>=2.14.0, <=3.0.0	mmseg>=0.14.1, <=1.0.0	mmcv-full>=1.3.8, <=1.4.0
0.17.1	mmdet>=2.14.0, <=3.0.0	mmseg>=0.14.1, <=1.0.0	mmcv-full>=1.3.8, <=1.4.0
0.17.0	mmdet>=2.14.0, <=3.0.0	mmseg>=0.14.1, <=1.0.0	mmcv-full>=1.3.8, <=1.4.0
0.16.0	mmdet>=2.14.0, <=3.0.0	mmseg>=0.14.1, <=1.0.0	mmcv-full>=1.3.8, <=1.4.0
0.15.0	mmdet>=2.14.0, <=3.0.0	mmseg>=0.14.1, <=1.0.0	mmcv-full>=1.3.8, <=1.4.0
0.14.0	mmdet>=2.10.0, <=2.11.0	mmseg==0.14.0	mmcv-full>=1.3.1, <=1.4.0
0.13.0	mmdet>=2.10.0, <=2.11.0	Not required	mmcv-full>=1.2.4, <=1.4.0
0.12.0	mmdet>=2.5.0, <=2.11.0	Not required	mmcv-full>=1.2.4, <=1.4.0
0.11.0	mmdet>=2.5.0, <=2.11.0	Not required	mmcv-full>=1.2.4, <=1.3.0
0.10.0	mmdet>=2.5.0, <=2.11.0	Not required	mmcv-full>=1.2.4, <=1.3.0
0.9.0	mmdet>=2.5.0, <=2.11.0	Not required	mmcv-full>=1.2.4, <=1.3.0
0.8.0	mmdet>=2.5.0, <=2.11.0	Not required	mmcv-full>=1.1.5, <=1.3.0
0.7.0	mmdet>=2.5.0, <=2.11.0	Not required	mmcv-full>=1.1.5, <=1.3.0
0.6.0	mmdet>=2.4.0, <=2.11.0	Not required	mmcv-full>=1.1.3, <=1.2.0
0.5.0	2.3.0	Not required	mmcv-full==1.0.5

问题解决：更换一下mmdet版本即可

pip install mmdet=={version}

、

参考文章：

1. 基于mmrotate旋转目标检测框架的使用_MFT小白的博客-优快云博客