A buffer mechanism of an artificial limb is provided, including a joint connecting base (20), an artificial limb connecting base (10), a first connecting rod (30) connected to a front side of the joint connecting base (20), a second connecting rod (40) connected to a rear side of the artificial limb connecting base (10), and a buffer cylinder (5, 60) disposed between the first connecting rod (30) and the second connecting rod (40) and having a sleeve (7, 61), a cylinder plug (6, 62) and a spring (8, 63). The cylinder plug (6, 62) is detachably disposed at one end of the sleeve (7, 61), the side surface of the first connecting rod (30) facing the second connecting rod (40) is disposed with a roller arm (50), an end of the roller arm (50) is pivotally connected with a roller (51), and the roller arm (50) contacts the end face of the cylinder plug (6, 62) by the roller (51). The present disclosure can reduce the wear rate of the cylinder plug (6, 62) and decrease the friction force.