A medical mechanical arm tail end device comprises a loading and unloading guide mechanism (1) used for loading and unloading a needle-shaped medical appliance an assembly (2) used for installing the loading and unloading guide mechanism (1) and a connecting plate (3) used for fixing the assembly (2) on a connecting rod (4) at the tail end of a mechanical arm. The loading and unloading guide mechanism (1) comprises four fixture bodies (11, 12, 13, and 14) of the same structure and a loading and unloading transmission mechanism (15) for driving the four same fixture bodies (11, 12, 13, and 14) to rotate. Each fixture body comprises a rotating shaft (116), an upper clamping plate (111), a lower clamping plate (114) and a plurality of guide sleeves (113). Under the action of the transmission mechanism (15), a closed hole (112) is formed by the corresponding guide sleeves (113) of two adjacent fixture bodies so as to guide an actuator and after the guidance is completed, the transmission mechanism (15) is reversely driven to separate the fixture bodies (11, 12, 13, and 14) from each other. The present invention is mainly used for automatically loading, unloading and guiding an ablation needle in a tumor ablation operation, ensures that a doctor has a sufficiently large operating space after the ablation needle is positioned/posed, and has high automation degree, high accuracy, simpleness for operation and strong coordinability between people and a machine.La présente invention concerne un dispositif médical dextrémité de bras mécanique qui comprend un mécanisme de guidage de chargement et déchargement (1) utilisé pour charger et décharger un accessoire médical en forme daiguille un ensemble (2) utilisé pour installer le mécanisme de guidage de chargement et déchargement (1) et une plaque de raccordement (3) utilisée pour fixer lensemble (2) sur une tige de raccordement (4) au niveau de lextrémité dun bras mécanique. Le mécanisme de guidage de chargement et déchargemen
