This paper proposes a novel microfluidic system for cell/microparticle recognition and manipulation utilizing a digital image processing technique (DIP) controlled optical tweezer under microfluidic configuration. Cell/microparticle samples are firstly electrokinetically sorted in a microfluidic channel and pass through an image detection region. Digital image processing technique is used to count and recognize the cell/particle samples and then sends control signals to generate laser pulses to manipulate the target cell/particles optically. The optical tweezer system is capable of catching, moving and switching the target cells within the microfluidic channel. The trapping force of the optical tweezer is also demonstrated utilizing the relationship between Stocks-drag force of microparticles and the applied electroosmotic flow. The proposed system provides a simple but high-performance solution for microparticle manipulation in a microfluidic device.