Abstract: With the rapid growth in demand for high-capacity tensile force measurement in advanced industries including aerospace, marine engineering and heavy equipment manufacturing, the performance of tensile calibration fixtures for force sensors has become crucial for ensuring measurement accuracy and reliability. This paper conducts a systematic analysis of the core mechanisms and critical factors in fixture design, examining error sources such as force transmission path deviations and structural deformation effects. Through comparative studies of material properties and optimized geometric design approaches, we establish selection criteria and manufacturing specifications for high-stiffness calibration fixtures. Furthermore, verification methodologies and maintenance protocols are presented, achieving ultimate control of fixture-induced errors within 0.038%.