The invention discloses a method for improving residue soil in a shield pressure cabin at high-permeability complex formations. The method comprises the steps that (1) geological conditions of the shield passing formations are checked out and collected; (2) several kinds of representative complex formation working conditions are selected, and according to the proportions of the formations on the shield passing sections under each working condition, the particle size distribution curve of particles in mixed residue soil of the complex formation excavation-cutting sections is calculated; (3) theobtained particle size distribution curve of the mixed particles and an existing particle size distribution curve conforming to soil pressure balance type shield and formation adaptability are compared, and the particle size and the admixing quantity of the fine particles needing to be admixed in the high-permeability complex formation improving process are estimated preliminarily; and (4) the shield passing formations are sampled on site, the kind and the admixing quantity of residue soil improving admixtures are determined. The method has the advantages that the mixed effect of the coarse particle formations and the fine particle formations in the complex formations are considered, therefore, compared with the method that only residue soil improving of the coarse particle formations isconsidered, the method better conforms to the actual situation, and accordingly the cost of a residue soil improving method generally only considering the most unfavorable coarse particle formations in the prior art is reduced advantageously.