Numerous children diagnosed with autism spectrum disorder (ASD) exhibit abnormal eye gaze pattern in communication and social interaction. In this study, we aim to investigate the effectiveness of the hide-and-seek virtual reality system (HSVRS) in improving gaze fixation abilities in children with ASD. Our hypothesis is that engaging in a hide-and-seek game within a virtual environment, particularly with a customized avatar resembling a familiar figure, would significantly enhance gaze fixation skills compared to traditional interventions without supplementary virtual reality (VR) intervention. In total, 36 children with ASD were involved in this pilot study in three groups: the avatar customized group, the avatar uncustomized group, and the control group. The control group only received human intervention, while the avatar group received additional VR-assisted interventions. The effect of HSVRS was measured by a six-point Likert subjective questionnaire and demonstrated significant improvements in gaze fixation abilities in the VR-assisted intervention groups compared to the control group (P = 0.006, 0.001). Moreover, the avatar customized group, which interacted with a familiar-looking avatar, obtained noticeable increments in gaze fixation metrics (P = 0.036, 0.005, 0.001). Experimental results show the effectiveness of utilizing VR technology to complement regular interventions in terms of improving gaze fixation abilities for young children with ASD.