The invention discloses a layered and sub-ring pouring controlling method for dome concrete through stage pressure holding of an LNG storage tank. The method comprises the following steps that (1) ring-direction pre-stress tensioning of the lower ring beam of a ring beam (1) is conducted; (2) air pressure jacking of a section steel net shell structure of a dome is conducted; (3) the pouring layerof the dome is divided into a first pouring layer and a second pouring layer from bottom to top, and each pouring layer is divided into multiple-stage annular areas Bj (j = 1,...,m, wherein m is no less than 2) from outside to inside; (4) concrete pouring of the first-stage annular area B1 of the first pouring layer is conducted, after the concrete of the first-stage annular area B1 of the first pouring layer reaches the preset strength value, pressurizing into the tank is conducted to the preset pressure, stage-by-stage continuous pouring of the first pouring layer is conducted in an in-tankpressure holding state, and the maintenance work is conducted; and (5), in-tank pressure is released, stage-by-stage continuous pouring of the second pouring layer is conducted, and the construction seam between the second pouring layer and the first pouring layer is in staggered lap joint.