方法在第二代残疾人证换发期间，对甘肃省安定区残疾人群进行智力鉴定。

Methods During replacing the certificate of disabled in the second period, the Anding district of Gansu province intellectual disabilities group were identified.

目的分析甘肃安定区智力低下人群主要致残原因，提出预防智力低下的有效措施。

Objective to explore the main reasons in disabled with mental retardation in Anding district of Gansu province, in order to proposed effective measures to prevent mental retardation.