Multifunctional sewage tank for oil field work

The utility model discloses a multifunctional sewage tank for oil field work. The multifunctional sewage tank for oil field work comprises four parts of a tank body structure, a liquid-level indicating part, a pneumatic control part, and a sand washing part; the tank body structure is an oval cuboid; two tank openings are arranged at the front and rear parts of the top part; a safety valve is arranged on a cover at the tank opening cover at the front end; a pneumatic switch cylinder is arranged on the cover of the tank opening at the rear end; water retaining grooves are arranged at two edges of the top part; a watering conduit and a discharge pipe are arranged at the upper part of the tail end of the tank body; a check valve is arranged on the watering conduit; an air intake valve is arranged at the front part of the check valve; a backwash valve is arranged at the lower part; a pneumatic valve is arranged at the bottom part; an anticorrosive coating is added to the inner wall of the tank body; a crawling la