The quartz crystal microbalance(QCM) is a mass-sensitive sensor with the advantages of high sensitivity and short response time. In order to expand the application of QCM technology in the field of liquid phase biomolecular sensing, a streptavidin-sensitive QCM sensor was successfully fabricated by electrochemically depositing the biomolecule-functionalized conducting polymers on the surface of QCM. The sensor can not only simultaneously realize the mass and electrochemical sensing of the streptavidin, but also has excellent anti-inteference ability against othor proteins. It has the potential to be further applied to liquid phase biochemical sensing and disease detection.