The invention relates to a new-energy unmanned intelligent cleaning ship for riverway algae. The new-energy unmanned intelligent cleaning ship for the riverway algae comprises a ship body, a harvesting guide device, ship wheels and a control system. The ship body is provided with a storage cabin used for storing the algae. The harvesting guide device is fixedly arranged on the front portion of the storage cabin. The algae are cut off by a harvesting disc. The cut-off algae are shifted to a transport cabin through a rotary collection frame. A conveying belt used for conveying the algae backwards after lifting the algae is arranged in the transport cabin. The control system comprises a gravity sensor, an onboard laser 3D detection imaging system, a radar system and a data analysis and control strategy functional module. The gravity sensor is used for monitoring the alga collection gravity and reminding a worker of a discharging requirement. The onboard laser 3D detection imaging system generates a 3D image by emitting lasers according to feedback reflecting data and sends the 3D image to a data analysis module, so that stretching and retracting adjustment of the harvesting disc, adjustment of flare angles of collection swing blades, adjustment of the rotating speed of the harvesting disc, adjustment of the rotating speed of the conveying belt, and adjustment of the rotating speed of the rotary collection frame are conducted.