The invention relates to a tubular valve for pressure maintaining coring. The tubular valve for pressure maintaining coring comprises a starting pipe, a pressure measuring joint, a sealing valve plate, a sealing valve seat and a double-bus joint, wherein the pressure measuring joint and the sealing valve seat are hermetically connected into a whole through the double-bus joint, and the sealing valve plate and the sealing valve seat are matched to form a dynamic sealing combination. The sealing valve seat is in a cylindrical shape, a sealed curved surface and a boss are arranged on the upper end surface of the sealing valve seat, and an arc surface, a groove and a pin shaft hole are formed in the boss. The sealing valve plate is a cylinder with an upper cambered surface and a lower camberedsurface, a sealed curved surface and a convex block are arranged at the outer periphery of the cylinder, and a pin shaft hole is formed in the convex block. The sealed curved surface of the sealing valve plate and the sealed curved surface sealing valve seat are a curved surface driven by a same three-dimensional mathematical curve, and the sealing valve plate and the sealing valve seat are turned over through a pin hinge to realize the opening of a sealing box. According to the tubular valve for the pressure maintaining coring, the inner through diameter of a coring tool is improved to the maximum extent, a more adaptive sealing valve part is provided for the coring tool, and the sealing mode is novel and reliable, so that the tubular valve for pressure maintaining coring is an importantpressure maintaining part of a rope coring tool and a conventional coring tool.