Abstract: Deep foundation pit deformation prediction is a crucial issue in geotechnical engineering. To efficiently and accurately predict the deformation conditions of deep foundation pit engineering, an optimized foundation pit deformation prediction method called MSD (mobilizable strength design) is proposed. Method: Based on the existing MSD method, the bending deformation energy of the retaining structure and the compressive elastic potential energy of internal supports are introduced to incorporate the retaining structure into the calculation system. The calculation steps for foundation pit deformation at different stages based on the optimized MSD method are presented. Taking the north shore shield work shaft foundation pit engineering of Ji’nan Yellow River Tunnel as an example, finite element simulation is conducted to analyze the deep foundation pit deformation. Taking measuring points at the midpoint on foundation pit long side as example, comparative analysis is carried out among the fieldmonitored results after internal support installation, the calculated results using optimized MSD method, and the numerical simulation results obtained from the finite element model. Result & Conclusion: With the increase of retaining structure buried depth, its deformation shows a trend of initial increase followed by a decrease. The peak horizontal deformation of the retaining structure is approximately 30 mm and occurs at a buried depth of 25 m. For a buried depth greater than 10 m, the calculated results using optimized MSD method align better with the fieldmonitored results than the numerical simulation results do. The calculated values using optimized MSD method and the fieldmeasured values exhibit a highly similar trend, although there still exists numerical deviation.