Automatic switch for roadway drainage

The utility model relates to an automatic switch for roadway drainage, comprising a floating ball and two mercoid switches, wherein the lower part of the floating ball is connected with a connecting pipe; the connecting pipe is internally provided with an anti-explosion wiring cock for a mine; the anti-explosion wiring cock for the mine is internally provided with the two mercoid switches; the two mercoid switches are connected in series, and a public node positioned between the two mercoid switches is additionally connected with a lead; three leads extend out from one end of the connecting pipe in all; and epoxy resin plugging layers are plugged on both ends of the connecting pipes. The automatic switch can control the start and the stop of a water pump with the height change of a water level, respectively replaces a normally open contact and a normally closed contact of the traditional operation button with the two mercoid switches and controls the on and the off of the contacts of the two mercoid switches