The invention discloses an omni-directional floating and wall-climbing underwater robot. The omni-directional floating and wall-climbing underwater robot comprises a sealed cabin, an underwater high-definition camera, a main control module, underwater sensing equipment, an omni-directional power system and a vertical power system, wherein the underwater sensing equipment is arranged inside and outside the cabin; the omni-directional power system and the vertical power system are arranged inside and outside the cabin; the omni-directional power system comprises four shrouded propellers, shrouded propeller steering devices, climbing devices and floating devices; the floating devices are arranged in the cabin; one end of each floating device is connected with the corresponding shrouded propeller; the shrouded propeller steering devices and the climbing devices are divided into upper and lower layers, are respectively arranged in the cabin and are connected with each other through respective transmission devices; the vertical power system is vertically arranged inside the cabin. The omni-directional floating and wall-climbing underwater robot has functions of floating, adsorption, wall-climbing and underwater monitoring, is flexible to move, high in practicality, high in maneuverability and wide in application range, can be used for omni-directional floating operation or omni-directional wall-climbing operation, is suitable for working in a narrow water area, and is compact in structure and convenient and easy to operate; the manufacturing cost is reduced; the accuracy of floating movement is improved.