The present invention is provided with a suction and explosion proof mechanism for a waterway accessory comprising a fixation part (10), which is disposed with a waterway and at least a channel, the waterway is disposed with at least an inlet hole (11) and a mutation cavity (12) connected to the inlet hole, the sectional area of the mutation cavity (12) is larger than that of the inlet hole; the channel is disposed with a first port and a second port, the first port is connected to the outside of the fixation part (10), the second port is situated in the mutation cavity (12); wherein the fixation part (10) is at least disposed with an explosion proof section and a suction section, the channel is disposed with a sealing unit (20), the sealing unit is deformable and movably disposed inside the fixation part (10), the sealing unit (20) can move between the explosion proof section and the suction section; when the waterway is open, the sealing unit is situated in the suction section, negative pressure generates inside the mutation cavity and works on the sealing unit to make the sealing unit deformed, the channel is open for suction; when the waterway is blocked, the pressure of the waterway increases and works on the sealing unit (20) and the channel is open to realize water and pressure discharge when the sealing unit (20) moves from the suction section to the explosion proof section.