With the continuous development of global satellite navigation system, the signal band resources are getting tighter and tighter, and the phenomenon of frequency band overlap is more and more obvious. BOC (Binary Offset Carrier) modulation based on spectrum splitting technology has been paid attention by many researchers, and BOC modulation adds a square wave subcarrier modulation on the basis of BPSK (Binary Phase Shift Keying) modulation to shift the frequency spectrum, make full use of the frequency band resources, and effectively solve the problem of band congestion and the compatibility of the navigation signals of multi-systems. However, the autocorrelation function of BOC signals has multiple side peaks, which leads to easy locking of the side peaks during the acquisition process and mis-acquisition, thus causing ambiguous acquisition problems. The paper firstly introduces the ambiguous problems in the process of BOC signal acquisition, then explores and analyses two types of unambiguous acquisition algorithms, finally summarizes the problems in the current BOC(n,n) unambiguous acquisition algorithms, and finally looks forward to the future development trend.