Bionic fish type underwater glider

The bionic fish type underwater glider comprises a fish head, a fish body and a fish tail which are connected in sequence, the fish body comprises a gliding shell, wings, flaps, an underwater steering mechanism, a buoyancy adjusting mechanism and a gravity adjusting mechanism; the fishtail comprises a tail shell, a tail fin and a swing driving mechanism; a deflectable flap is arranged on each wing, and reverse deflection of the two flaps is controlled by a set of underwater steering mechanism arranged in the gliding shell, so that underwater steering of the gliding shell is realized; the buoyancy adjusting mechanism and the gravity adjusting mechanism are arranged in the gliding shell and jointly control the gliding shell to float and dive; the tail shell is connected with the gliding shell, and the swing driving mechanism is arranged on the tail shell and connected with the tail fin so as to control the tail shell and the tail fin to swing synchronously or independently, and gliding advancing in the linear s