Missing key(s) in state_dict: Unexpected key(s) in state_dict:

如果加载的预训练模型之前使用了torch.nn.DataParallel()，而此时的训练并没有使用，则会出现这样的错误。
解决方案有两个：
1：此时的训练加入torch.nn.DataParallel()即可。
2：创建一个没有module.的新字典，即将原来字典中module.删除掉。

解决方案1：

model = torch.nn.DataParallel(model)
cudnn.benchmark = True

解决方案2：

# original saved file with DataParallel
state_dict = torch.load('myfile.pth')
# create new OrderedDict that does not contain `module.`
from collections import OrderedDict
new_state_dict = OrderedDict()
for k, v in state_dict.items():
    name = k[7:] # remove `module.`
    new_state_dict[name] = v
# load params
model.load_state_dict(new_state_dict)

解决方案3：

model.load_state_dict({k.replace('module.',''):v for k,v in torch.load('myfile.pth').items()})

You probably saved the model using nn.DataParallel, which stores the model in module, and now you are trying to load it without . You can either add a nn.DataParallel temporarily in your network for loading purposes, or you can load the weights file, create a new ordered dict without the module prefix, and load it back.
参考：https://discuss.pytorch.org/t/solved-keyerror-unexpected-key-module-encoder-embedding-weight-in-state-dict/1686/3