According to upper load and deformation control requirements between the metro shields, a shallow treatment scheme of soft foundation for fill road above shield is proposed. Combined with the mechanics principle of the scheme, the relevant calculation formulas are derived. In order to further study the deformation and stress characteristics of soil and shield structure caused by the subgrade treatment and construction, based on the construction of an urban road project above Hangzhou Metro Line 5, the soft foundation treatment and construction process of the road above shield are analyzed by numerical simulation. The analysis results are compared with the calculated data derived from the formula. The correctness of the calculation method is verified. The research results can provide reference for the design of similar projects.