The invention provides an offline automatic brick stacking assembly line. The offline automatic brick stacking assembly line comprises a brick arranging device, a brick transferring device and a brick stacking device, wherein brick layers can be reduced by at least one row or one line relative to the upper layer or the lower layer through the brick arranging device, the corresponding brick layer can be rotated by a predetermined angle relative to the upper layer or the lower layer through the brick transferring device, so that a formed brick stack is more stable, the brick layers in the reduced row or line can be pulled to be separated while the brick layers in the non-reduced rows or lines are stacked, so that a gap is formed between every two adjacent rows or lines, then stacking is conducted, after the formed brick stack is packaged, a transporter can be inserted into the gaps conveniently for grabbing, and when two gaps exist, the two insertion angles of a forklift can be inserted for transportation. In this way, the offline automatic brick stacking assembly line has the advantages that brick stacking quality is high, efficiency is high, the formed brick stack can be transported by the transporter such as the forklift conveniently, the degree of mechanization and the degree of automation are high, the assembly line can be adapted to various types of bricks and various brick forming machines, and practicability is high. The invention further provides a brick stacking method. All the functions can be achieved effectively by the adoption of the brick stacking method.