On-line dynamic weighing is an important part of the unpacked foods packaging production line, which can realize the functions of error prevention, leakage prevention, packing and filling. It was investigated the formation of the structure, control system, sorting mechanism, data processing and preservation of weighing workstation in this study, based on the function of continuous online dynamic weighing an subsequent processing in packaging production line. The interval sampling and numerical averaging methods were used to collect and calculate dynamic weight data, and the difference of the product between the dynamic weight value and the static were minimized. The system could be quickly built according to the function of achieving the weight of the product collection, comparison, sorting, packaging etc. Therefore, this system could be used widely for rapid secondary development of docking packaging line, with the simple structure, low cost and high accuracy.