Objective To investigate the visual acuity and refractive state of preschool children in the Cheng Guan district of Lanzhou， to identify the children outside the normal range of vision and refraction for early-stage detection and treatment. Methods It was a cross-sectional study. 2 841 children ranging in age from 3 to 6 years who were enrolled in 10 kindergartens in the Cheng Guan district of Lanzhou were selected through cluster random sampling. And 2 754 cases （5 508 eyes） in fact tested. The children were examined with a standard logarithmic visual acuity chart and the Suresight Vision Screener handheld autorefractor. The measurement data were analyzed by t test or ANOVA， classificated data were analyzed by χ² test or linear trend test. Results The incidence of abnormal visual screening was 13.9% at the preschool level. There was a difference in visual disorder detection rates among different age groups （χ²=31.80， P<0.05）， and the prevalence of abnormal vision declined with age （χ²lineartrend=31.59， P＜0.05）. Refractive error accounted for 13.13% of the total number and， as age increased， the incidence of compound hyperopic astigmatism and simple hyperopia gradually declined （χ²lineartrend=16.01， P＜0.05； χ²lineartrend=9.11， P＜0.05）. Conclusion The incidence of abnormal vision identified from screening preschool children who ranged in age from 3 to 6 years declined with age in the Cheng Guan district of Lanzhou city. These findings indicate that visual acuity improves as children age. Ametropia is the most common condition in preschoolers. Hyperopia constitutes the majority of refractive errors identified in the visual screening of preschool children， which is consistent with visual acuity and refractive development in children.