In view of the problems that frequency band resources of aviation communication are limited, and aviation broadband communication system is inevitably interfered with narrowband communication system, a jamming detection algorithm is proposed in frequency domain based on the maximum posterior probability criterion to achieve accurate jamming suppression in combination with the frequency threshold excision algorithm. In this paper, the algorithm structure of the jamming detection algorithm based on the maximum posterior probability criterion is established, and the formula of the detection threshold is derived from the hypothesis testing theory. In addition, the performance of single carrier frequency domain equalization is compared to that of the orthogonal frequency division multiplexing under narrowband jamming, and the performance advantages of single carrier frequency domain equalization are explored, providing theoretical and experimental support for its potential application in broadband aviation communication. And then, the proposed jamming detection algorithm is applied to single carrier frequency domain equalization. The simulation results show that this algorithm achieves yet a lower error rate at both low and high jamming-to-signal ratio (-20~20 dB) in comparison with the traditional jamming detection algorithms based on mean, variance, and median under conditions of the interference bandwidth being occupied 20%, 10% and 5% in the signal bandwidth respectively.