The invention relates to novel substituted quinoline derivatives shown as the general formula I and medicinal acid addition salts of the novel substituted quinoline derivatives. The compounds provided by the invention are specially defined as the specification, wherein R1 and R2 are respectively independent methyl, ethyl or benzyl, or R1 and R2 and N connected with R1 and R2 can form 4-methyl-piperidyl or morpholinyl, and n=1 or 2. The invention also relates to preparation methods of the compounds provided by the invention. Pharmacological activity screening tests show that the compounds have remarkable hyperplasia preventing effects for cancer cells in vivo and in vitro, and parts of compounds have remarkable tumor suppression activity, such as lung cancer, liver cancer, breast cancer and pancreatic cancer. Particularly, the tumor inhibiting rate of the pancreatic cancer PANC (Pancreatic Cancer Cell)-1 is up to 46.7%.