pytorch官方链接: https://pytorch.org/get-started/previous-versions/

安装指令：conda install pytorch==1.9.0 torchvision==0.10.0 torchaudio==0.9.0 cudatoolkit=11.3 -c pytorch -c conda-forge
报错：Solving environment: unsuccessful initial attempt using frozen solve. Retrying with flexible solve.

使用下面的指令：pip install torch==1.9.0+cu111 torchvision==0.10.0+cu111 torchaudio==0.9.0 -f https://download.pytorch.org/whl/torch_stable.html

下载太慢！！：

换源：pip install torch==1.9.0 -i http://pypi.mirrors.ustc.edu.cn/simple/ --trusted-host pypi.mirrors.ust c.edu.cn

成功~