In order to meet application needs of measurement-while-drilling（ MWD） device in some environment like small-bore oil well

high-frequency vibration and intense impact

using fiber-optic gyroscope（ FOG） and quartz flexibility accelerometer as sensor unit

design accelerometer signal sampling circuit

and miniaturization navigation calculating module includes system on programmable chip（ SOPC）

SDRAM and FLASH

complete functions such as signal collecting of sensors

error compensation

navigation calculating and communicating with upper PC. Inertial measurement unit（ IMU） consists of power module

sensor unit and navigation computer

then fabricate MWD device which is  38 mm. The result shows that when the angle of inclination is bigger than 5°

the model machine can meet the needs of precision of attitude resolving（ error of inclination and tool face angle error are less than ± 0. 2°

and error of azimuth is less than ± 2°）.