The utility model discloses a high altitude construction technical field's aerial working platform's extension work platform, including the bottom plate, the last skin weld of bottom plate has a fixedrail, and the left surface central authorities of fixed rail run through and are equipped with the passageway, and articulated on the rear side inner wall of passageway have an emergency exit, and the right side of bottom plate is equipped with traverser, traverser's the left surface and the right side overlap joint of fixed rail, the utility model discloses an outwards promote first backup pad,the messenger wins and forms orthogonal angle between backup pad and the second backup pad, the length of bottom plate has been extended to first backup pad, make aerial working platform can realize the extension of length, the slide outwards slides among two sets of slip subassemblies, slide left or right what the sliding sleeve corresponded on annular slide rail, make traverser's first backup pad support to the left side or the right side of slide, make aerial working platform's space to obtain extending at left right direction, and various functions, has higher practicality.