Different empathic responses are often reported in autism but remain controversial. To investigate which component of empathy is most affected by autism, we examined the affective, cognitive, and motivational components of empathy in 25 5‐ to 8‐year‐old autistic and 27 neurotypical children. Participants were presented with visual stimuli depicting people's limbs in painful or nonpainful situations while their eye movements, pupillary responses, and verbal ratings of pain intensity and empathic concern were recorded. The results indicate an emotional overarousal and reduced empathic concern to others' pain in autism. Compared with neurotypical children, autistic children displayed larger pupil dilation accompanied by attentional avoidance to others' pain. Moreover, even though autistic children rated others in painful situations as painful, they felt less sorry than neurotypical children. Interestingly, autistic children felt more sorry in nonpainful situations compared with neurotypical children. These findings demonstrated an emotional overarousal in response to others' pain in autistic children, and provide important implications for clinical practice aiming to promote socio‐emotional understanding in autistic children.