An organism paracentesis device comprises a first tube member and a second tube member. The first tube member comprises an injection tube filled with a medicament, a piston and a first syringe needle. The second tube member comprises a sampling tube and a second syringe needle. Both ends of the second syringe needle are in the form of syringe needle. Using one end of the second syringe needle to penetrate a cover of the sampling tube which is vacuumed, such that the second syringe needle's the other end which is penetrating into an organism will extract a sample from the organism because of the vacuumed sampling tube. The medicament filled in the injection tube is ejected both when the first and second syringe needles are penetrating into and pulled out of the organism, so as to avoid the cells of sampled organism being spread to other places.