In recent years, with the rise of printed electronics technology, printed flexible sensors have garnered widespread attention. To predict the performance of sensors before actual fabrication, in this paper, the bending strain and resistance response of the sensor’s functional layer were simulated using COMSOL Multiphysics 6.0 software, and the effects of different carbon black/graphene fill ratios on the sensor’s bending performance were explored. The simulation results indicated that resistance increases with the bending angle during the bending process, and the bending-resistance characteristics are better when the carbon black to graphene mass ratio is 2:1. Subsequently, flexible strain sensors were fabricated using screen-printing technology and their bending performance was tested. The experimental results demonstrated that the sensors have good linearity (R² = 0.9851), favorable response and recovery times (approximately 1 and 2 s, respectively), low hysteresis (4.88%), and better cyclic stability when repeatedly bent at 0∘−20∘ compared to 0∘−90∘. The experimental results were consistent with the simulation results. This study provides a new perspective on the design of flexible strain sensors through synchronized experiments and simulations, which is expected to significantly reduce the cost of prototype development.