In geological exploration， coal mining， oil exploration and geothermal resource development， near-bit MWD plays an important role in real-time detection of engineering parameters such as tool attitude and formation geological parameters， and implementation of guided drilling. This paper introduces the working principle of MWD system focusing on the physical model of attitude angle and its solution， at the same time， based on the domestic high temperature resistant programmable logic gate array （FPGA） chip， three-axis acceleration sensor and three-axis reluctance sensor， the near bit MWD system is designed. The test results show that the performance index of the system can meet the practical engineering application.