A biopsy needle, comprising: an inner needle assembly , comprising a first plug-in connection portion plugged in with a fastener , wherein the first plug-in connection portion comprises two first outer limiting walls arranged in parallel and a first limiting plate located between the two first outer limiting walls , and the first limiting plate is provided with a first protrusion ; an outer needle assembly , comprising a second plug-in connection portion plugged in with the fastener , wherein the second plug-in connection portion comprises two second outer limiting walls arranged in parallel and a second limiting plate located between the two second outer limiting walls , and the second limiting plate is provided with a second protrusion ; and the fastener , comprising a third plug-in connection portion plugged in with the first plug-in connection portion, and a fourth plug-in connection portion plugged in with the second plug-in connection portion, wherein the third plug-in connection portion comprises two first inner limiting walls that have a T-shaped longitudinal section and that match the first outer limiting walls , and a third limiting plate arranged between the two first inner limiting walls and matching the first limiting plate , wherein the third limiting plate is provided with a first groove mating with the first protrusion ; and the fourth plug-in connection portion comprises two second inner limiting walls that have a T-shaped longitudinal section and that match the second outer limiting walls , and a fourth limiting plate arranged between the second inner limiting walls and matching the second limiting plate , wherein the fourth limiting plate is provided with a second groove mating with the second protrusion , wherein the first outer limiting walls are arranged perpendicular to the first limiting plate , and a first gap is provided between each of the first outer limiting walls and the first limiting plate . an inner needle assembly , comprising a first plug-in connection portion plugged in with a fastener , wherein the first plug-in connection portion comprises two first outer limiting walls arranged in parallel and a first limiting plate located between the two first outer limiting walls , and the first limiting plate is provided with a first protrusion ; an outer needle assembly , comprising a second plug-in connection portion plugged in with the fastener , wherein the second plug-in connection portion comprises two second outer limiting walls arranged in parallel and a second limiting plate located between the two second outer limiting walls , and the second limiting plate is provided with a second protrusion ; and the fastener , comprising a third plug-in connection portion plugged in with the first plug-in connection portion, and a fourth plug-in connection portion plugged in with the second plug-in connection portion, wherein the third plug-in connection portion comprises two first inner limiting walls that have a T-shaped longitudinal section and that match the first outer limiting walls , and a third limiting plate arranged between the two first inner limiting walls and matching the first limiting plate , wherein the third limiting plate is provided with a first groove mating with the first protrusion ; and the fourth plug-in connection portion comprises two second inner limiting walls that have a T-shaped longitudinal section and that match the second outer limiting walls , and a fourth limiting plate arranged between the second inner limiting walls and matching the second limiting plate , wherein the fourth limiting plate is provided with a second groove mating with the second protrusion , wherein the first outer limiting walls are arranged perpendicular to the first limiting plate , and a first gap is provided between each of the first outer limiting walls and the first limiting plate . <EOS>