Objective To explore the association between long working hours, anxiety symptoms, and insomnia symptoms among footwear industry workers, and to examine the mediating effect of anxiety symptoms between long working hours and insomnia symptoms. Methods A total of 710 workers from 15 footwear manufacturing enterprises in Guangdong Province were selected as study subjects using a stratified random sampling method. Long working hours, anxiety symptoms, and insomnia symptoms among the workers were assessed using the National Key Population Occupational Health Literacy Monitoring Questionnaire, the Chinese version of the Generalized Anxiety Disorder Self-Rating Scale, and the Self-Rating Sleep Questionnaire. Binary logistic regression was applied to analyze the associations of long working hours and anxiety symptoms with insomnia symptoms, and a mediation effect model was used to examine the mediating role of anxiety symptoms. Results The workers with long working hours accounted for 69.6% of participants. The detection rates of anxiety symptoms and insomnia symptoms were 17.0% and 20.7% in these workers, respectively. Binary logistic regression analysis showed that both long working hours and anxiety symptoms were influencing factors for insomnia symptoms (both P<0.01). Mediation analysis indicated that long working hours had a direct effect on insomnia symptoms, accounting for 67.9% of the total effect. Anxietysymptoms played a partial mediating role between long working hours and insomnia symptoms, with an effect value of 0.18 (95% confidence interval 0.07-0.30, P<0.01), accounting for 32.1% of the total effect. Conclusion Both long working hours and anxiety symptoms are influencing factors for insomnia symptoms among the footwear industry workers, and anxiety symptoms partially mediate the impact of long working hours on insomnia symptoms.