Based on the practical engineering of the subway station constructed by shallow tunnel, according to the site monitoring data, it is concluded the regular pattern of ground settlement that constructed in CRD method. The longitudinal ground settlement curve affected by the spacing between step 1 and step 3 obviously, there are 5 phases in the curve: the first slow growth phase, the first rapid growth phase, the second slow growth phase, the second rapid growth phase and the stable phase; Although the time of the two rapid growth phases is short, the proportion of the ground settlement in these phases is about 65%-85% of the total ground settlement; it also can be known that basing on the practical monitoring curve, the zone of longitudinal ground settlement is about D on the method of CRD. The lateral ground settlement curve in line with the Gaussian curve, the settlement formula could be calculated according to Peck formula, on the base of these, this paper mainly discusses the relationship between K which means settlement trough width parameter and H/D , the results shows that when H/D is about 1.2, the K is minimum.