Evaluation of forward looking infrared（FLIR）scene matching algorithm is a problem pressing for solution.This paper focuses on the estimation of matching probability,which is an important indicator of algorithm evaluation.Noise,blur,resizing and rotation of the infrared image,caused by surrounding factors,are simulated.Bernoulli trial is implemented to estimate the matching probability of single image.And then matching probability of partial image sequence is calculated according to the relationship between matching probability of single image and that of the partial image sequence.This paper presents a new method for effective evaluation of FLIR scene matching algorithm.