Abstract: A method for preparing battery grade and high purity grade lithium hydroxide and lithium carbonate from high-impurity lithium sources includes steps for preparation of a refined lithium salt solution, preparation of battery grade lithium hydroxide, preparation of high purity grade lithium hydroxide, preparation of high purity grade lithium carbonate and preparation of battery grade lithium carbonate. The system to carry out the preparation includes a refined lithium salt solution preparation subsystem, a battery grade lithium hydroxide preparation subsystem, a high purity grade lithium hydroxide preparation subsystem, a high purity grade lithium carbonate preparation subsystem and a battery grade lithium carbonate preparation subsystem arranged in turn according to production sequence. A combination of physical and chemical treatment methods are used to treat the high-impurity lithium sources having variations in lithium contents, impurity categories, and impurity contents.