I think it is better to choose China Ocean University or Guangxi University as the mechanical direction for postgraduate entrance examination.
I am a student of Haida University. Personally, I think Haida is better. It is a comprehensive university, but it is actually an institution with a long history and rich experience in running schools. It is also a 2 1 1 985 institution, which will win fame in the future. It can also be used as a springboard to enter the chemical research institute in the future. Every year, many senior students are admitted to the research institutes directly under the Chinese Academy of Sciences.