The paper is concerned with the micro-flow self-sensing actuators,the work of which is based on the secondary piezoelectric effect. The piezoelectric ceramic stack can yield micro-displacement due to its first inverse piezoelectric effect. Therefore,we apply this micro-displacement to cell micro-flow injection. Moreover, due to the charge of the secondary direct piezoelectric effect,the piezoelectric ceramic stack is able to detect the force and displacement in the injection by itself. The experiments of first inverse piezoelectric effect and secondary direct piezoelectric effect are conducted. The experiment results show that,subjected to 0- 60 V input,the piezoelectric ceramic stack can generate 13. 45 μm displacement,and control accuracy can achieve 2 nm. It can completely meet the needs of cell micro-flow injection. Also,the experiments demonstrate that the micro-displacement due to the first inverse piezoelectric effect can be well self-sensed by the electric charge due to the secondary direct piezoelectric effect. The paper is concerned with the micro-flow self-sensing actuators, the work of which is based on the secondary piezoelectric effect. Thus, we apply this micro- displacement to cell micro-flow injection. Furthermore, the charge of the secondary direct piezoelectric effect, the piezoelectric ceramic stack is capable to detect the force and displacement in the injection by itself. The experiments of first inverse piezoelectric effect and secondary direct piezoelectric effect are conducted. The experiment results show that, subject to 0-60V input, the piezoelectric ceramic stack can generate 13. 45 μm displacement, and control accuracy can achieve 2 nm. It can completely meet the needs of cell micro-flow injection Also, the experiments demonstrate that the micro-displacement due to the first inverse piezoelectric effect can be well self-sensed by the electric charge due to the se condary direct piezoelectric effect.