The invention discloses an oil concentration rapid detection apparatus for oily sewage, comprising a micropump, a capacitance detection electrode, a micro-channel chip, a body case, a capacitance amplifier, a signal acquisition card, a microprocessor, a display, a printer, and an alarm. A micro channel and the capacitance detection electrode are integrated in the micro-channel chip. A cross section of the micro channel has a rectangular shape. The micro channel comprises an inlet section, a detection section, and an outlet section. The microprocessor is provided with built-in programs of signal acquisition, filtering, comparison, analysis and counting, and data processing. In the invention, the micro-channel chip technology is used, detection members have small sizes, a detection circuit has high integration, signal processing and computing are mainly completed by the microprocessor, and therefore equipment has a relatively simple structure. The micro-channel chip of the invention can be repeatedly used, is rapid in detection, has little sample consumption, has low energy consumption, has common and relatively cheap equipment working parts, and therefore overall cost is relatively low. The oil concentration rapid detection apparatus for oily sewage is simple to operate, has a circuit board of high integration, has a compact structure, is convenient for carrying, and is convenient for on-site detection.