Large-drift-diameter high-pressure filtering device for pressure-controlled drilling

A main body of the large-drift-diameter high-pressure filtering device is a manifold with two large-drift-diameter channels, the manifold comprises the two channels, and each channel is provided with a large-drift-diameter high-pressure filtering element and a large-drift-diameter manual flat valve. Drilling fluid returned from a wellhead enters the pressure control choke manifold after being filtered by one of the passages of the device, and once the filtering device of the passage is blocked, the standby passage can be manually switched to recover the flowing of the drilling fluid. The invention has the advantages of simple structure and large pipeline drift diameter, increases the area of a diversion outlet, reduces the resistance and the risk of blocking and pressure building of pressure control equipment under the condition that various performances are satisfied, and effectively solves the problems of low flow monitoring precision, inaccurate annulus pressure calculation, easy blocking of a manifold and