In this paper, the design ideas including the software and the hardware such as key electric circuits of the automatic weather station based on embedded Linux operating system are introduced. The high resolution ADC (analog-to-digital convertor) is used to achieving data characters. The system based on the bus structure makes the system can be connected with various weather sensors. Any substitution of the weather sensors neither need to change the software nor the hardware of main collector. Not only the program source codes are given, but also some essential problems which should be paid attention are suggested. Practical application shows that this system has advantages such as high precision，high stability, low power consumption. Experimental results proof that the system is accordance with the design criteria of the second-generation automatic weather station in China.