The invention discloses a sampling device for water quality, which includes a shell, a GPRS communication module, a water sampling control module, a water sample storage module, a second belt wheel, blades, a second rotary shaft, a mounting board, a filter plate, a storage battery and an inverter. The GPRS communication module is installed on the top of the inner side of the shell. The device, firstly, measures the depth and width at a target cross section of river to determine number of sampling vertical lines, number of point positions and sampling positions; then by means of auto-calculatednumber of sampling points, sampling heads are set and a sampling surface is formed to simultaneously collecting water samples in same section at different positions of the water body; furthermore, bymeans of water quality analysis technology, pollution liabilities at left and right shores and on surface and bottom layers of the river are designated, thus supplying technical support to accurate distinguishing of pollution sources in the river; meanwhile, the device is driven by water energy and solar power generation, so that the device is energy-saving and environment-friendly.