The invention provides a deironing and sterilization liquid distributing tank for oilfield sewage. The liquid distributing tank comprises a tank body, clamping grooves, a protection frame, a stirrer, an oxygen pump and a hose with screening holes. The tank body is open. The protection frame is arranged in the tank body and used for supporting the stirrer. The oxygen pump is arranged outside the tank body and used for supplying oxygen containing gas into the tank body. The exhaust end of the oxygen pump penetrates through the tank body and is communicated with one end of the hose with the screening holes. The clamping grooves are formed in the inner circumferential wall of the tank body and used for fixing the hose with the screening holes. The hose with the screening holes can be fixed to the inner circumferential wall of the tank body through all the clamping grooves, or is fixed to the inner circumferential wall of the tank body only through part of the clamping grooves. The liquid distributing tank has the advantages of being simple, practical, low in cost, safe, environmentally friendly, simple in operation process, low in labor intensity, thorough in sterilization, more remarkable in effect and the like, no additional bactericide needs to be added, and the problem about the compatibility of a sewage treatment agent and a polymer is avoided.