Hallux valgus is a common progressive deformity of the hallux, affecting 23% of adults. Patients may experience foot pain and walking disability. The use of orthosis is a common non-surgical way to alleviate the symptoms. The majority of the current orthoses are uncomfortable to wear, leading to poor compliance and adversely affecting the treatment efficacy. Given the paucity of studies on the design of orthoses, this study used a scientific method based on foot anthropometry and biomechanics to create an in-shoe hallux valgus orthosis using appropriate textile materials, 3D scanning and 3D printing technologies to provide the proper amount of corrective force and improve the fit and comfort of the orthosis. The finite element model is used to evaluate the biomechanical foot-orthotic interaction, and the parametric effects of various orthotic designs and material properties can be studied. The results of this study provide valuable information for designing ergonomic hallux valgus orthoses.