Fracture correction is important orthopedics operation and can be performed by unilateral external fixator. Due to pin deviations being inevitable during the operation, searching the impacts of pin deviation on the fracture correction and fixator joint adjustment are important. This study puts forward evaluation index with sensitivity analysis for investigating the impact of three orientation deviations and three position deviations on fracture correction. Meanwhile, based on a clinical case from a 28-year-old female, the influence of pin deviation on the adjustment of fixator joints was analyzed by inverse kinematic method. Different pin deviations have different sensitivity; the sensitivity of orientation deviation is relatively larger than position deviation. The existence of pin deviation will result in the change of the adjustment value of fixator joints. In addition, the experiments of seven situations were established to verify the analytical results. This study revealed the sensitivity of different pin deviations which can also be used to predict the adjustment value of fixator joints and the accuracy of fracture correction. This research also helps to reduce operation time and decrease damage to soft tissue by reducing the frequency of inserting pins.