According to the imaging principle of an aerial infrared camera, the indexes for evaluating a camera are proposed. Then, the Analytic Hierarchy Process (AHP) is used to get the weight vector of each index and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is used to calculate the corresponding indexes. Finally, the feasibility of this method is verified in some examples. The calculation result shows that space resolution and temperature sensitivity are the two most sensitive indexes of an aerial infrared camera. This work is helpful to the development and improvement of aerial infrared cameras in the future.