In the first part of this paper, the design and adjusting method for LC impedance matching network are presented. By this method, the power absorbed by the transducer from an oscillator can exceed 95%. In the optimum matching state, the modulation depth of zero order light can be up to 92% when LiNbO3-dense flint acousto-optic modulator is driven by 0.5 W BF power.In the second part, an oscillator circuit and its adjusting method are presented. Its frequency is continuously tunable over a range of 54.3~54.7 MHz and its stability is about (1~2)×10-6.