The invention relates to the technical field of water body detection, and specifically relates to a detection device for water body turbidity. The detection device comprises a controller, a connection flat cable, a laser driver, a tunable laser, a photoelectric detector array and a light wave escape device, wherein the controller is connected with the laser driver and the photoelectric detector array through the connection flat cable; the laser driver is connected with the tunable laser; the light wave escape device is connected with the tunable laser. A water body is irradiated by the tunable laser, transmitting light escapes through the light wave escape device, and light intensities in various direction are detected by virtue of the photoelectric detector array, thus obtaining an accurate turbidity value; the water body turbidity can be much accurately measured, and real-time measurement can be realized without the need of sampling pre-treatment and the need of other chemicals for carrying out chemical reactions, so that secondary pollution is avoided; the detection device is simple and convenient, high in sensitivity, and capable of realizing online or portable measurement.