The utility model discloses a prevent feeding system that flows backwards, including feeder sleeve and bypass pipe, the discharge end of feeder sleeve is equipped with governing valve and interlocking valve in proper order, bypass pipe one end is connected on the feeder sleeve of governing valve front end, and the bypass pipe other end is connected on the feeder sleeve of interlocking valve rear end, be equipped with the pressure difference value display instrument on the bypass pipe, the interlocking arithmetic unit is connected to the pressure difference value display instrument, the pressure antithetical couplet lock controller of interlocking valve and the flow display control regulator of governing valve are connected to the interlocking arithmetic unit. The utility model discloses can solve because of under a variety of causes leads to the fact the circumstances of the serious not enough or cutout of material flow, other material of mixed zone can not instead be scurried and got into the feeder sleeve and take place the solid substance that the reaction generated non - expectancy and take place to stop up or lead to the fact the trouble, leads to the fact long -time device overhaul, influences effective production efficiency's problem. The utility model discloses simple reliable, the economically feasible of principle, operate moreover reliable and stable, overhaul maintain also little.