This kind of stacker firstly conveys the goods to the designated position through the conveying system. Under the precise command of the control system, the mechanical arm or grabbing device of the stacker grabs the goods one by one and puts them on the pallet according to the preset stacking mode. These palletizing modes can be flexibly adjusted according to the shape, size and weight of the goods, for example, for rectangular boxes, staggered or flush palletizing can be used to ensure stability. Pallets full of goods are transported out, and new pallets automatically enter the stacking position, and the whole process is carried out circularly, thus realizing continuous stacking operation