A fluid mixing assembly includes a connecting cap, a three-way pipe and a connecting member; the connecting cap has a first connecting portion; the three-way pipe is connected to the connecting cap, and has a second connecting portion, an output portion and a cavity, wherein the second connecting portion, the output portion and the cavity communicate with each other; the connecting member is connected to the connecting cap, and has a pin-hole channel, wherein the pin-hole channel has a first end bore and a second end bore opposite to the first end bore, the first end bore communicates with the first connecting portion, and the second end bore communicates with the second connecting portion and the output portion.