The invention is a method for preparing electrochemical microflow control chip with sunk copper electrode, used in preparing electrochemical microflow control chips. The method: using microchannel mould to thermally press PMMA (polymethyl methacrylate) substrate to obtain microchannel; using microelectrode mould to thermally press another PMMA substrate to obtaining microelectrode sinkage ans spattering Cu on this PMMA and using etching and wet-corroding processes to make sunk Cu microelectrode; adopting thermal interlinking mode to sealing the two PMMA substrates to obtain electrochemical microflow control chip with sunk Cu electrode. Its effects and benefits: adopting thermal pressing, spattering, etching and wet-corroding methods to obtain sunk Cu electrode, integrating the sunk Cu electrode on the microflow control chip so as to raise the yield of manufacturing chips and simultaneously adopting Cu as the material of working electrode for electrochemical detecting, largely reducing the cost of chip. This chip can be widely applied to sugar detection in biochemical analysis.