The improvement of safety performance of construction workers heavily lies in safety training and great improvement has been achieved in training technology, training materials and training organisation. Currently, the form of training and induction based on traditional lectures and workshop studies has been innovated and enriched by digital and e-learning technologies and applications, such as immersive visualization techniques like Virtual Reality (VR), Augmented Reality (AR) and game engines. The visualization techniques allowed workers to enhance their safety capabilities by playing the safety training game in virtual scenarios. However, the validation of its effectiveness was measured with either self-reported questionnaire or the improvement in safety performance and productivity. This research proposed a framework to directly validate the effectiveness of virtual reality in safety training by measuring the degree of emotional arousal with electromyography (EMG). Specifically, the degree of inducement of fear was measured during safety trainings with pictures, videos and VR. The higher degree of fear was induced, the more effective the safety training was. In this way, this research provided a novel approach to prove the effectiveness of the immersive visualization techniques and a possible framework to further identify important personal and environmental factors of safety training process.