The invention discloses a central circulating water supply system of workshops. The central circulating water supply system of the workshops comprises a circulating water tank, a plurality of water supply system units, a central water distributing pipe and a standby pump. Each water supply system unit comprises a branch water inlet pipe connected between a water outlet of the circulating water tank and a water inlet of a reaction kettle, a branch water return pipe connected between a water outlet of the reaction kettle and a water inlet of the circulating water tank, and a main pump arranged on the branch water inlet pipe. The central water distributing pipe is connected with one ends, close to water outlets of the main pumps, of the branch water inlet pipes, and all the branch water inlet pipes are communicated by the central water distributing pipe. A water inlet of the standby pump is connected with the water outlet of the circulating water tank, and a water outlet of the standby pump is connected with the central water distributing pipe. According to the central circulating water supply system of the workshops, water solution delivered by all the water supply system units is communicated by the central water distributing pipe, water is supplied according to requirements of all the production workshops, and energy waste is avoided; besides, the whole water supply system just needs to be provided with one standby pump, and investment of equipment funds is reduced.