The utility model provides a confluence device for a gas extraction drill site, belongs to the field of mining equipment, and aims to solve the problems that coal cinder and accumulated water in a drill hole cannot be thoroughly cleaned when gas, coal cinder and accumulated water generated in the extraction process are treated at present, and an extraction drill hole and a confluence pipe are easily blocked due to grid-connected belt extraction. The bottom of the confluence barrel is connected with the support frame; at least six first interfaces are formed in the middle upper part of the sidesurface of the confluence barrel; each first interface is connected with one end of a first high-pressure rubber pipe; the other end of the first high-pressure rubber pipe is connected with a drill hole of an extraction drill site; a second interface is formed in the side bottom of the confluence barrel; the second interface is connected with one end of a second high-pressure rubber pipe; the other end of the second high-pressure rubber pipe is connected with a negative-pressure water discharging device in an extraction drill site, a third connector is arranged at the top of the confluence barrel and connected with one end of a third high-pressure rubber pipe, the other end of the third high-pressure rubber pipe is connected with negative pressure of a well bottom working face, a slag discharging opening is formed in the bottom of the confluence barrel, and a butterfly valve is arranged on the slag discharging opening.