Design of an effective detection scheme for high-speed frequency-hopping signal is the groundwork for Link-16 signal detection. This paper presents a detection scheme based on multichannel radiometer structure. The communication mechanism and high-speed FH characteristic of Link-16 are analyzed in detail. Then, to surmount the deficiencies caused by directly applying multichannel radiometer in Link-16, this paper designs a new adaptive threshold algorithm and a new judicative rule, presents a feasible modification rule for the channel detection results and finally based on multichannel radiometer achieves the Link-16 signal detection. The simulation results of this scheme show that the threshold algorithm of this detection scheme has a good adaptability to the amplitude of input signal, which can be used to effectively solve the problem of Link-16 signal detection under low SNR and to make the channel detection results independent of the background noise.