In order to achieve portable test

traditional multi-coil detection structure is simplified as single coil structure. The measurement system uses digital signal processor（ DSP） to construct dtetcting circuit

excite single coil by pulse

and then detect signal is output by the single coil

greatly simplifying the measurement. At the same time

fast Fourier transform（ FFT） algorithm is combined with chirp Z transform（ CZT） algorithm to improve the detection precision of millimeter-level magnetostrictive sensor. This system realizes simultaneous detection of magnetostrictive sensors with two different size of sensors

which are 4 mm and 5 mm. The experimental results show that the sensitivity of the sensor with length of 4 mm is 0. 384 1（ k Hz/μg） and the sensitivity of the sensor with length of 5 mm is 0. 219 8（ k Hz/μg）. This sensor has wide applications value in portable biochemical detecting instrument.