?The fluid distribution in the microchannel of ICEC (Integrated Capillary Electrophoresis Chip) was simulated using ANSYS software.The relations between the microchannel structure and flow velocity under different sample injection modes were obtained.Then the optimized channel structure was chosen by the width of 16?μm,the depth of the chip was determined 10?μm and the effective dividing length of 3.5?cm with round corner channel.The chip structure was designed.