A collapsible prefabricated mechanical soft wall is disclosed. The collapsible prefabricated mechanical soft wall comprises: a housing having a top board, a bottom board and a plurality of side boards formed therebetween, wherein two of the side boards opposite to each other have a slot, respectively, the two slots are parallel to each other, and a long opening is formed on the bottom board; a plurality of movable wall parts each rotatably connected to two adjacent ones; and an adjusting rod with two ends movably installed in the slots, respectively.