In the Marvel series, Captain Mei could pick up Thor's hammer because the hammer itself had some mysterious power that could give the holder supernatural power. In the movie Thor, a hammer was sent to Earth and landed on a man named Steve Roger. Although Steve Roger was an ordinary man, he had some special abilities such as strong willpower and indomitable spirit, which allowed him to pick up the hammer and use its power. The reason why Captain America picked up the hammer was to protect the earth and mankind. He hoped to use the power of the hammer to defeat the evil forces and protect mankind from harm. The hammer also represented justice and strength in the movie, so Steve Roger's picking up the hammer also symbolized that he had received the bonus of justice and strength.