A combination weighing device and an operating method thereof are disclosed. The device comprises N material treating units, a mainboard, chutes (10, 11, 16, 17) and discharging hoppers (12, 13, 14), wherein the material treating units are used for receiving materials, outputting the 
weight value of materials and discharging materials according to the discharging 
control signal from the mainboard; the mainboard is used for selecting materials by combinatorial calculation based on the present-period 
weight value during every period and outputting the discharging 
control signal to weighing hoppers (7); the chutes (10, 11, 16, 17) are used for collecting the materials through a discharging 
route, discharging the materials to the discharging hoppers (12, 13, 14), after a discharging 
route is determined; the discharging hoppers (12, 13, 14) are used to separately collect materials discharged from the chutes (10, 11, 16, 17) during the same weighing period and send the materials to a packing 
machine; each material treating unit comprises a linear vibrator (5), a feed hopper (6), a weighing hoper (7), a weighing sensor used to weigh the materials in the weighing hoper (7), a processor and a A / D converter which is connected with the weighing sensor and the processor, N material treating units are connected with the mainboard 
signal together by two data receiving and delivering communication 
converters of the mainboard.