By means of FT245BL,this paper achieves multipoint data acquisition on RS485 fieldbus through using notebook PC by Universal Serial Bus and using waveform graph directly express realtime processing data to analysis easily by hostcomputer writing with MFC. Detail the composition of the various parts of the system，including hardware circuit and hostcomputer software design. Then through collecting the data of development boards on both nodes on the RS485 fieldbus to simulate the sensor on RS485 fieldbus and show the waveform by hostcomputer .Finally,checking the feasibility of the system successfully.