Abstract:  According to the fact that it occurred data loss, unreasonable storage, low accuracy of decoding when receiving the realtime BDS／GPS data. This paper presented a program of the realtime data acquisition and decoding, taking the development board based on STM32F103RET6 microcontroller as carrier. It achieved data storage and calculation, and got high precision pseudorange, carrier observations. Meanwhile, it calculated the pseudorange single point positioning by combined BDS／GPS.The results show that the standard deviation is about 9 meters and RMSE is about 14 meters, the development board is proved stable and easy to use. This is the basis of data realtime acquisition, decoding and differential computation of multi-GNSS.