the invention discloses a preparation method and system of high purity lithium carbonate . the preparation method comprises : concentrating carbonic acid type salt lake bittern , then heating up to saturate , crystallize and separate out the lithium carbonate , and collecting crystals to obtain refined salts of lithium carbonate ; flushing the collected refined salts of lithium carbonate with distilled water with a temperature above 60 ° c . to dissolve sodium - potassium salts therein ; drying to obtain the high purity lithium carbonate . for the lithium carbonate purification process , chemical reagents are not needed , the refining and purification of the lithium carbonate may be finished by physical operation , the purification of the refined and purified lithium carbonate is up to above 95 %, which is beneficial for reducing the transportation cost at the later stage and the further purified cost . the process has an extremely low requirement for transportation and does not contaminate the environment at the same time .