The invention discloses a method for preparing a medical porous tantalum material. The method comprises the following steps of: mixing a poly ethanol aqueous solution and tantalum powder to obtain slurry, wherein the mass concentration of the poly ethanol aqueous solution is 2 to 8 percent; injecting the slurry into an organic foam by vibrating and pressurizing, wherein the vibrating frequency is 20 to 80 times/min; drying; degreasing; sintering, namely raising temperature to 1,500 to 1,800 DEG C at the speed of 10 to 20 DEG C/min under the vacuum degree of 10<-4> to 10<-3>Pa, preserving heat for 120 to 240 minutes, cooling to 200 to 300 DEG C along with a furnace, raising temperature to 1,500 to 1,800 DEG C at the speed of 10 to 20 DEG C/min again, preserving heat for 180 to 240 minutes, raising temperature to 2,000 to 2,200 DEG C at the speed of 5 to 10 DEG C/min, and preserving heat for 120 to 360 minutes; cooling; and performing thermal treatment, namely raising temperature to 800 to 900 DEG C at the speed of 10 to 20 DEG C/min under the vacuum degree of 10<-4> to 10<-3> Pa, preserving heat for 240 to 480 minutes, cooling to 400 DGE C at the speed of 2 to 5 DGE C/min, preserving heat for 120 to 300 minutes, and cooling to room temperature along with the furnace. The porous tantalum prepared by the method is very suitable to be used for the medical implant material for replacing bearing bone tissues, and biocompatibility and the mechanical property can be guaranteed simultaneously.