The invention relates to an environmental control and protection method for excavation of a large-scale ultra-deep foundation pit, which includes the steps: firstly, using various domestic and foreign analytical methods for deformation of retaining structures, comparing results of the methods for the retaining structures to measured values, and determining a reasonable analytical method for deformation of the extra-large-diameter ultra-deep foundation pit; secondly, comparing and analyzing settlement modes of the ground around the pit, estimating influencing factors of ground settlement under the action of the factors, comparing the ground settlement obtained by the analytical methods to the measured values and researching; thirdly, analyzing horizontal deformation, vertical deformation and safety of a pile foundation of a viaduct under conditions of foundation pit dewatering and excavation; and fourthly, determining duct safety evaluation indexes and standards, analyzing duct internal force in different deformation distribution modes, and evaluating safety of the duct under the excavation conditions. Compared with the prior art, the method has the advantages that safety for surroundings is high, the analytical method for the large-scale ultra-deep foundation pit is effective and reasonable, and the like.