The invention discloses a small multifunctional unmanned cleaning ship for a river channel. The small multifunctional unmanned cleaning ship for the river channel comprises glass hulls, carbon fiber frameworks, a garbage interception net, frame rods, a moving motor, a monitor, a storage battery, a data acquisition detection box and a weed cutting machine. The double glass hulls are fixedly installed through the two carbon fiber frameworks. The garbage interception net is fixedly installed on sterns of the glass hulls through the frame rods and bolts. The data acquisition detection box is installed at the upper ends of the carbon fiber frameworks. The monitor electrically connected with the storage battery is installed on the data acquisition detection box. The moving motor is installed atthe rear end of the data acquisition detection box. The weed cutting machine is fixedly installed at the bottom ends of the carbon fiber frameworks through bolts. By the adoption of the small multifunctional unmanned cleaning ship for the river channel, the device design is suitable for river bottom sonic detection. The cleaning ship has the beneficial effects of being capable of sweeping floatinggarbage, cutting and collecting weed, obtaining water quality samples, acquiring water surface information, detecting the water level and conducting water flow detection, economical, applicable, convenient and quick to use, high in attendance rate, easy to operate, quiet, environment-friendly, and free of tail gas emission.