The invention discloses an electromagnetic muscle bionic cavity membrane medusa robot and relates to a medusa robot, in particular to the electromagnetic muscle bionic cavity membrane medusa robot. The invention aims at solving the problems of low efficiency, high noise and poor controllability of a conventional bionic medusa robot. The electromagnetic muscle bionic cavity membrane medusa robot comprises a casing component, an electromagnetic muscle bionic driving mechanism, a tail tentacle rudder mechanism, four draining and flooding tanks and four water pumps; an electromagnetic muscle bionic cavity is arranged in the casing component; two draining and flooding tanks are arranged on one of two sides of the electromagnetic muscle bionic driving mechanism; one water pump is arranged in each draining and flooding tank; the tail tentacle rudder mechanism is arranged on the lower surface of the casing component. The electromagnetic muscle bionic cavity membrane medusa robot disclosed by the invention belongs to the field of robots.