C:\Users\leahj>C:\Users\leahj\AppData\Local\Programs\Python\Python36\Scripts\pip3 install cv2
Collecting cv2
  Could not find a version that satisfies the requirement cv2 (from versions: )
No matching distribution found for cv2

C:\Users\leahj>C:\Users\leahj\AppData\Local\Programs\Python\Python36\Scripts\pip3 install opencv
Collecting opencv
  Could not find a version that satisfies the requirement opencv (from versions: )
No matching distribution found for opencv

C:\Users\leahj>C:\Users\leahj\AppData\Local\Programs\Python\Python36\Scripts\pip3 install opencv2
Collecting opencv2
  Could not find a version that satisfies the requirement opencv2 (from versions: )
No matching distribution found for opencv2

 

pip3 install opencv-python



参考：
https://cloud.tencent.com/developer/ask/188024