Abstract: In order to solve multi-signal processing simultaneously in an optical coherent receiver system,a frequency measurement system that employs acousto-optic deflection technology and fiber-based coherent optical detection was designed based on acousto-optic deflection principle and characteristics of multiple signals co-existing and transmitting in the complex and dense electromagnetic environment.The acousto-optic interaction and beam deflection of different frequency signals were analyzed in theory.Through numerical simulation of multi-frequency intermodulation,the solution of reducing intermodulation of multiple signals was obtained.An experimental platform for handling multiple signals was constructed with space light injecting into fiber. Experimental result shows that real-time signal capture capability of the system is very strong and carrier frequency measurement of multi-signal can be realized in the system bandwidth.The test data displays that the frequency resolution is less than 0.1 MHz and the interception rate is up to 100%.