This paper reports on the design and control of a novel large-range micro-injector which is used for biological cell micro-injection. The device is actuated by one smart piezoelectric (PZT) actuator. The injector can not only provide the large-range displacement but also a tiny shape that can be assembled under the usual microscope system conveniently. The output of the device is amplified by a bridge-type mechanism amplifier. Analytical model of the injector is developed to facilitate the design. Finite-element analysis (FEA) simulation study is carried out is to verify the performance of the injector. A prototype of the model is fabricated for experimental test. The result shows that the maximum output of the device is 103 micrometers. By applying the sliding model control, the positioning error can be reduced within 2 um, which is demonstrated by the experimental study.