The invention discloses a furnace inside atmosphere purifying method for a continuous binder removal sintering furnace. According to the furnace inside atmosphere purifying method, a gas purifying and separating device communicating with the inside of a furnace body is arranged outside the continuous binder removal sintering furnace and conducts tail gas treatment on tail gas generated inside the furnace body, after the tail gas passes through the gas purifying and separating device, impurities and recyclable gas are generated, the impurities are collected, and the recyclable gas is input into the furnace body again for cyclic utilization. The furnace inside atmosphere purifying method for the continuous binder removal sintering furnace has the advantages that the binder-removing and debonding effect is good, hydrogen can be recycled, the tail gas can be purified, the consumption of the hydrogen can be reduced, cost can be reduced, and the productivity of products is higher, wherein the above advantages cannot be achieved in the prior art.