To investigate the fire characteristics and evolution under the coupled influence of various factors during an aircraft fire accident, this study takes the double-deck aircraft A380 as an example. Based on the concept of digital twins, an integrated aircraft information mirror digital model is established by combining sensor data from the aircraft. This model elucidates the fire simulation approach of physical entities and virtual space under the digital twin concept. Fire simulation software is used to simulate the aircraft fire, obtaining time–space distribution values of fire parameters such as CO concentration, temperature, and visibility range, thereby enhancing the analytical capability of aircraft fire accident simulations. Taking the cabin luggage fire as an example, the results show that when a luggage fire occurs in the middle of the upper deck cabin, within the 90s emergency evacuation time of the aircraft, the fire parameters in the upper deck cabin do not reach the ASET (Available Safe Egress Time) criteria, except for the position near the fire source where the visibility drops below 5 m at 44 s. The fire parameters in the other locations have no significant impact on personnel. In the lower deck cabin, due to the partitioning of the upper and lower decks, no significant changes in fire parameters are observed.