Pool fire caused by fuel leakage seriously threatens engine operation and aircraft safety. To deeply understand the complicated physical mechanisms of pool fire in engine fan cavities，temperature variation characteristics of double fuel pool fire were investigated. Firstly，the physical and numerical models of the CFM56-7B engine fan cavity were established based on the software FDS. Secondly，simulated temperature variations of single fuel pool fire were validated against measurements of the Trent 800 engine fan cavity，and then grid independence was analyzed. Finally，the fire development process and temperature variation characteristics of double fuel pools were analyzed within the fan cavity using several detectors and slices. The results indicated two phases for temperature variation of the double fuel-pool fire in the engine cavity，including an increment state and a quasi-steady state. Moreover，temperature variation magnitude was affected by distances between the detectors and the fuel pools. Fuel-pool fire flame propagation inclined to the left side of the fan cavity，causing an increment of fire temperature on the left side. Plume floating，flame fusion，fusion expansion，and full flame coalescences were observed in the axial direction of the cavity.