The invention discloses a mesh portion dry vacuum dehydration system used for a multi-cylinder long mesh paper machine and belongs to the field of accessories of paper making equipment. The mesh portion dry vacuum dehydration system comprises a dry vacuum box which is provided with a dehydration board in contact with a forming table, the middle of the dry vacuum box is a dry vacuum box vacuum chamber, and the length of a mesh portion dry vacuum dehydration system area is increased by 10%-50% than that of a mesh portion dry vacuum dehydration system area of a traditional multi-cylinder long mesh paper machine with the same width and the same speed. The mesh portion dry vacuum dehydration system has the advantages that pulp dwell time is long, the dehydration degree is high, orderly distribution of pulp fibers and padding can be effectively promoted, and the paper sheet forming effect is good, and solves the problems of a traditional mesh portion dry vacuum dehydration system.