The present invention provides a method for constructing a chair-type, self-supported earth retaining wall used for retaining external forces such as earth pressure prior to an excavation. The method of the present invention forms a first column of piles having a plurality of piles arranged along the circumference of the region to be excavated. Subsequently, the method comprises forming a second column of piles having a plurality of piles by consecutively perforating a plurality of holes by a predetermined spacing at predetermined positions outwardly from the first column of piles, along the circumference of the region to be excavated, inserting H-beams into the respective holes, filling left and right spaces of the webs of the H-beams with soil, and filling the outer spaces of the flanges of the H-beams with a flowable stiffening material. The method subsequently comprises interconnecting the first column of piles and the second column of piles by a connection member. The first column of piles and the second column of piles are formed along the circumference of the region to be excavated, with an outward spacing, and connected to each other by the connection member.The present invention provides a method for constructing a chair-type, self-supported earth retaining wall used for supporting external forces such as earth pressure prior to an excavation. The method of the present invention comprises forming a first pile array 20 having a plurality of piles 22 arranged along a circumference of an region to be excavated. Subsequently, the method comprises forming a second pile array 30 having a plurality of piles arranged along a circumference of the to-be-excavated region by consecutively drilling a plurality of boreholes 31 at predetermined intervals at predetermined positions outwardly spaced apart from the first pile array, inserting H-beams into the respective boreholes, filling left and right spaces of webs 34 of the H-beams 32 with soil 40, and filling the outer spaces of flanges 36 of the H-beams with a flowable hardening material 50. The method subsequently comprises fixedly interconnecting the first pile array and the second pile array using a connection member. The first pile array and the second pile array are formed in such a fashion as to be outwardly spaced apart from each other along the circumferences of the to-be-excavated region, and are connected to each other by the connection member to construct an underground earth retaining wall.