The invention relates to a liquid phase chip detector based on a quantum dot, comprising a liquid phase chip, an exciting light source, a microflow channel, an optical imaging system and an image analyzing system, wherein the liquid phase chip is a liquid phase chip of a quantum dot coding microballoon; the exciting light source takes light with single wavelength as exciting light and refracts the exciting light into a detection area of the microflow channel which is the microflow channel of a wide sheath channel with width of 0.1-5mm; the optical imaging system is CCD (Charge Coupled Device)or CMOS (Complementary Metal-Oxide-Semiconductor Transistor) or a spectrum imaging system; and the image analyzing system comprises computer hardware and image analyzing software and is used for receiving and processing data from the optical imaging system. The liquid phase chip detector has the advantages of stable and strong fluorescence, low possibility of photobleaching, wideband excitation, narrow transmission spectrum, higher stability, sensitivity and resolution, remarkably improved detection speed and efficiency, simple and compact whole structure and can be used for detecting thousands of microballoons at each second.