The invention relates to a combined expansion reed. The combined expansion reed comprises a telescoping chain and reed needles. The reed needles are mounted on a reed plate seat. The telescoping chain is a parallelogram hinge telescoping mechanism formed by upper chain plates, lower chain plates and hinge shafts hinging the upper chain plates and the lower chain plates. The telescoping chain is provided with at least two positioning columns. The bottom of the reed plate seat is provided with positioning holes. The reed plate seat is mounted on the telescoping chain in an inserted manner by the positioning columns inserting into the positioning holes. The combined expansion reed is simple in structure, convenient to assemble, high in precision after assembling, capable of keeping the equal-distance distribution of the reed needles during telescoping adjusting, and high in durability.