Objective To propose a quick and low-cost personalized diabetic foot modeling and insole design scheme, so as to reduce the plantar pressure accurately. Methods The foot model of the patient was constructed by scaling the model with foot feature parameters, to make biomechanical analysis on plantar pressure. By means of numerical mapping model of insole elasticity and plantar pressure, the three-dimensional (3D) personalized insole model with gradient modulus was constructed. The insole was then manufactured via 3D printing technology and used for experimental validation. Results The related mechanical parameters from finite element prediction of the foot model constructed by the scaling modeling method were close to those of the CT reconstructed model, and the maximum error was controlled within 15%. Compared with wearing the normal insole, the peak pressure of the personalized insole was effectively reduced by 20%. The time and economic cost of this simplified design was reduced by approximately 90%. Conclusions The design scheme of the diabetes insole shortens the design cycle, and the personalized insole can effectively and accurately reduce the sole pressure, and reduce the risk of foot ulcer, which provides a technical basis for the promotion of the personalized diabetes insole.