The invention aims at providing a compartment fire development area evaluation method, which is characterized in that a closed single compartment is divided into two layers, an upper hot smoke layer and a lower cold air layer; and assuming that energy and mass between the two layers are only transferred through plume, no heat exchange between the closed compartment and the exterior exists, the smoke and the air are ideal gas with identical molecular weight, a height variation relation of the single compartment fire smoke layer along the time and the temperature variation relation of the upper smoke layer along the time can be obtained. The method is low in calculation quantity, the system requirement on the calculation speed can be met, and simultaneously the evaluation method can predict the main characteristics of fire of ships and warships.