Mechanical arm capable of lifting on load

The invention relates to a mechanical arm capable of lifting on load. The overall height is low in the folded state, transportation is convenient, large-range on-load lifting can be achieved during unfolding, and therefore shaking of hoisted goods is reduced, and using is safe. A mechanical arm capable of lifting on load comprises a base, a folding arm, a basic arm, a folding arm cylinder, a variable amplitude cylinder, a lower swing rod and an upper swing rod, the base, the folding arm and the basic arm are sequentially connected through pin shafts, the cylinder rod end of the folding arm cylinder, the end of the lower swing rod and the end of the upper swing rod are connected through the same pin shaft, and the cylinder barrel end of the folding arm cylinder is hinged to the folding arm. The other end of the lower swing rod and the other end of the upper swing rod are hinged to the folding arm and the basic arm respectively, and the two ends of the variable-amplitude cylinder are hinged to the base and the