On windows, DLL load failed while importing CV2: the specified module could not be found

system: windows 10

1. I installed anaconda3. But it isn't added in the system PATH.
2. I installed an official python3.8.2 also. And the official python3.8.2 is added in the system PATH
3. I compile opencv source code with visual studio 2019 and I select the python3.8.2 for interpreter. As a result I get a python binding cv2.pyd. And all .dll relate to opencv are added to system PATH.
4. I copy the cv2.pyd to official python directory(site-packages). Then I import cv2 in official python3.8.2. However an ImportError occured: DLL load failed while importing CV2: the specified module could not be found.
5. In order to find out the problem, I use anaconda to create an environment with python3.8.1, and I install numpy and matplotlib in the environment. The same operation, I copy the cv2.pyd to the new environment(site-packages). Then I import cv2 in the python3.8.1. Something magical happened, the cv2.pyd works well in the environment with python3.8.1.

The final picture is official python dir and anaconda python environment dir.

So, what does the anaconda do when I create a new environment? Why the cv2.pyd(I build it in official python3.8.2) can work in anaconda python3.8.1 environment but not the official python3.8.2? Is there any document related to my question?

More immediately, How can I use the cv2.pyd in official python version?

Official python3.8.2 directory screenshot:

Anaconda python3.8.1 environment directory screenshot: