A blood plasma and blood cell separation device includes a first body, a blood plasma separation membrane and a second body. The first body has an injection port. The blood plasma separation membrane is disposed on the first body. The second body is movably assembled to the first body and has a collecting stage. The collecting stage has a collecting surface and a sampling recess on the collecting stage. When a blood enters the blood plasma separation membrane from the injection port of the first body, a blood plasma in the blood plasma separation membrane is separated by a capillary force between the collecting stage of the second body and the blood plasma separation membrane, and the blood plasma enters in the sampling recess by a relative movement between the first body and the second body.