Collecting and switching device for oil and gas of underwater wellhead

A collecting and switching device for oil and gas of an underwater wellhead comprises an oil control cover, a quick crossover coupling, an anti-settling baffle and a sinking structure, wherein the quick crossover coupling is arranged on the top of the oil control cover; the anti-settling baffle is arranged on the bottom of the oil control cover; the sinking structure is arranged on the bottom of the anti-settling baffle; the quick crossover coupling comprises a gate valve, a stand pipe, a plurality of bevel gear sealing devices, a funnel-shaped structure and a hose coupling; the stand pipe is arranged on a port of the upper portion of the gate valve; the bevel gear sealing devices surround the stand pipe; the funnel-shaped structure is connected to the stand pipe; the hose coupling penetrates in the funnel-shaped structure and is connected with the quick crossover coupling; and the hose coupling is provided with a gripping handle which is matched with a manipulator of an underwater robot. When a leaking accident occurs, a leaking point can be fastened by the collecting and switching device rapidly and effectively; after a pipe of the leaking point is switched, leaked oil or gas can be delivered to an offshore engineering ship through an oil or gas delivery pipe; the problem that loss and marine pollution which are caused by oil or gas leakage is solved; and safety of marine petroleum exploitation engineering is guaranteed.