A sea-cucumber underwater identification based on active electrolocation is proposed to solve the problems of the existing underwater identification technology affected by underwater visual conditions and heavy equipment. Firstly, by measuring the electrical conductivity of sea-cucumber and other materials, the feasibility of using active electrolocation technology for sea-cucumber identification is evaluated. Then, a sea-cucumber identification test platform is built by simulating the sea cucumber habitat environment. And the influence of lift-off distance and recognition signal characteristics on the recognition effect of sea-cucumber is studied. Secondly, the recognition effect of sea cucumber in different posture and different positions is studied. Finally, the underwater discrimination effect of stone and steel block with sea-cucumber is explored. Results show that, at the lift-off distance of 50 mm, the perturbation potential change rate caused by sea cucumbers is about 5% , which is obviously different from the influence mechanism of other objects on the active electric field. This technology can effectively identify sea cucumbers. The resolution of the recognition effect is related to the liftoff distance of the sensor and the characteristics of the electrical signal. This technology can effectively identify sea-cucumbers in different postures and different environmental backgrounds.