The invention discloses a water mixing device of a water distributing and collecting device. The water mixing device is characterized in that an electric three-way regulating valve, a circulating water pump and a
water temperature sensor are arranged on a
water supply pipeline where a cooling and heating water inlet
pipe is connected with a water
distributor, a three-way
pipe and an electric stop valve are arranged on a water return pipeline where a water collector is connected with a cooling and heating water outlet
pipe, and the three-way pipe is combined with a water return
branch pipe for connecting return water on the water return pipeline into the electric three-way regulating valve; and the water mixing device further comprises an indoor
dew point temperature probe, an indoor temperature sensor, a
temperature control panel, an electric three-way regulating valve, a circulating water pump, a
water temperature sensor and an electric stop valve, wherein the indoor
dew point temperature probe and the indoor temperature sensor are electrically connected with the
temperature control panel. Meanwhile, the invention further discloses a control method of the water mixing device. The water mixing device is simple in structure and stable in operation, the water mixing device is arranged at the
radiation tail end of a
fresh air conditioning
system and can be directly connected into a conventional
air conditioning water
system, condensation caused by too low
water supply temperature in summer can be avoided, and the situation that the service life of components and radiant tubes is affected by too high
water supply temperature in winter can be prevented.