A threshold assembly for a container, the threshold assembly is arranged at a door end of the container, wherein the threshold assembly comprises: an outer end plate comprising a horizontal portion and a vertical portion which is arranged vertically downward at one end of the threshold assembly toward an outer side of the container from an outer side of the horizontal portion; a horizontal connecting member (280, 580) connected to a floor of the container; and a middle connecting member (270, 570) connected to the outer end plate and the horizontal connecting member (280, 580), wherein one end of the middle connecting member (270, 570) in a horizontal direction extends to a position where the horizontal portion and the vertical portion of the outer end plate intersect; an inserting opening which opens toward the top of the horizontal connecting member (280, 580), and a clamping groove (271, 671) which is inclined downward and toward the outer end plate from the inserting opening are arranged at the other end of the middle connecting member (270, 570) in the horizontal direction; and an inserting portion (283, 683) matched with a structure of the clamping groove (271, 671) is arranged at one end of the horizontal connecting member (280, 580), and is capable of being inserted into the clamping groove (271, 671) through the inserting opening to connect the horizontal connecting member (280, 580) and the middle connecting member (270, 570), characterised in that the clamping groove (271, 671) is configured to have an approximately L-shaped vertical cross section, and comprises an inclined portion (278, 578) inclined downward and toward the outer end plate from the inserting opening, a hook portion extending substantially horizontally from a lower end of the inclined portion (278, 578), and a step portion (275, 575, 675) laterally protruding from the inclined portion (278, 578) to limit lateral movement of the inserting portion (283, 683). an outer end plate comprising a horizontal portion and a vertical portion which is arranged vertically downward at one end of the threshold assembly toward an outer side of the container from an outer side of the horizontal portion; a horizontal connecting member (280, 580) connected to a floor of the container; and a middle connecting member (270, 570) connected to the outer end plate and the horizontal connecting member (280, 580), wherein one end of the middle connecting member (270, 570) in a horizontal direction extends to a position where the horizontal portion and the vertical portion of the outer end plate intersect; an inserting opening which opens toward the top of the horizontal connecting member (280, 580), and a clamping groove (271, 671) which is inclined downward and toward the outer end plate from the inserting opening are arranged at the other end of the middle connecting member (270, 570) in the horizontal direction; and an inserting portion (283, 683) matched with a structure of the clamping groove (271, 671) is arranged at one end of the horizontal connecting member (280, 580), and is capable of being inserted into the clamping groove (271, 671) through the inserting opening to connect the horizontal connecting member (280, 580) and the middle connecting member (270, 570), characterised in that the clamping groove (271, 671) is configured to have an approximately L-shaped vertical cross section, and comprises an inclined portion (278, 578) inclined downward and toward the outer end plate from the inserting opening, a hook portion extending substantially horizontally from a lower end of the inclined portion (278, 578), and a step portion (275, 575, 675) laterally protruding from the inclined portion (278, 578) to limit lateral movement of the inserting portion (283, 683).