The parameter design of every module including optical waveguide, mode splitter, acoustic waveguide and interdigital transducer is the key to the design of acoustic-optical tunable filter. The parameters of interdigital transducer are designed, and the design ideas of radio frequency drive circuit and matching circuit are put forward. Taking micro controller unit (MCU) AT89C52 as the master controller in circuit control system, the test result is obtained by a 158 MHz frequency synthesizer.