The present invention relates to a bone marrow extractor. The bone marrow extractor of the present invention has an outer needle rod with a case having an upper portion and a lower portion in communication with each other. The case has a front end with a crushing blade and a rear portion with a stopper groove. An inner needle rod which has a main body having a front end with a crushing blade and a rear portion with a connector is inserted into the outer needle rod. The main body of the inner needle rod has an outer surface from which a stopper lever is protruded. The front end of the main body of the inner needle rod is protruded from the front end of the case of the outer needle rod when the stopper lever is fitted into the stopper groove. The inner needle rod and the outer needle rod cooperate with each other to crush bones through a rotation when the head of a driving means coupled to the connector operates. After bone crushing, only the inner needle rod is removed, and the outer needle rod is kept within the human body to suck and extract bone marrow in a syringe-like manner.