Abstract: In order to make the actual flow velocity of micro-channels be consistent with the theoretical value and make sure that the amplification process and the steps of PCR chip are completed exactly, it is needed to do real-time measurement and flow control of the actural work fluid flow condition.The fluorescence signal value of the micro-channel filled with the strong active fluorescence PCR reagent was about 4 times as great as that of the empty micro-channel and 10 times as great as that of the micro-channel filled with the negative fluorescence PCR reagent in the 39 cycled micro-channels of biological PCR micro-fluidic chip.Based on the above fact, a proposal was made that the real-time fluorescence detection micro-sensor should be set up on the chip to sense the information feedback, so the condition of the velocity of flow in the microchannel could be feed backed in time and the velocity of flow could be controlled.