A sewing system comprising: a plurality of sewing machines; and a management device that manages the plurality of sewing machines, with the plurality of sewing machines and the management device being connected to each other via a terminal so as to be capable of communicating bidirectionally, each of the plurality of sewing machines including: a memory for storing parameter data obtained by digitizing an adjustment amount of an adjustment function of a seam, wherein the parameter data includes at least one of a feed dog height, a feed pitch, a feed trajectory, a pressing pressure, and a thread tension and the adjustment function includes at least one of a feed dog height adjustment function, a feed pitch adjustment function, a feed trajectory adjustment function, a pressing pressure adjustment function, and a thread tension adjustment function; and an adjustment unit that adjusts the adjustment function of the seam by the adjustment amount corresponding to the parameter data in the memory, so that a sewing operation of the sewing machine is adjusted in accordance with the work contents of a step in a sewing line or a condition of the material and the like of a cloth, and the sewing system being characterized by the management device including: a management unit that separately manages the parameter data of the plurality of sewing machines; and a delivery unit that simultaneously delivers the parameter data to each of the plurality of sewing machines. a plurality of sewing machines; and a management device that manages the plurality of sewing machines, with the plurality of sewing machines and the management device being connected to each other via a terminal so as to be capable of communicating bidirectionally, each of the plurality of sewing machines including: a memory for storing parameter data obtained by digitizing an adjustment amount of an adjustment function of a seam, wherein the parameter data includes at least one of a feed dog height, a feed pitch, a feed trajectory, a pressing pressure, and a thread tension and the adjustment function includes at least one of a feed dog height adjustment function, a feed pitch adjustment function, a feed trajectory adjustment function, a pressing pressure adjustment function, and a thread tension adjustment function; and an adjustment unit that adjusts the adjustment function of the seam by the adjustment amount corresponding to the parameter data in the memory, so that a sewing operation of the sewing machine is adjusted in accordance with the work contents of a step in a sewing line or a condition of the material and the like of a cloth, and the sewing system being characterized by a memory for storing parameter data obtained by digitizing an adjustment amount of an adjustment function of a seam, wherein the parameter data includes at least one of a feed dog height, a feed pitch, a feed trajectory, a pressing pressure, and a thread tension and the adjustment function includes at least one of a feed dog height adjustment function, a feed pitch adjustment function, a feed trajectory adjustment function, a pressing pressure adjustment function, and a thread tension adjustment function; and an adjustment unit that adjusts the adjustment function of the seam by the adjustment amount corresponding to the parameter data in the memory, so that a sewing operation of the sewing machine is adjusted in accordance with the work contents of a step in a sewing line or a condition of the material and the like of a cloth, and the sewing system being characterized by the management device including: a management unit that separately manages the parameter data of the plurality of sewing machines; and a delivery unit that simultaneously delivers the parameter data to each of the plurality of sewing machines. a management unit that separately manages the parameter data of the plurality of sewing machines; and a delivery unit that simultaneously delivers the parameter data to each of the plurality of sewing machines.