Abstract: This paper aims to address the issues of low positioning accuracy and insufficient operational efficiency in the calibration process of α、 β surface contamination α、β surface contamination monitors. Based on theJJG 478—2016 specification, a high-precision positioning bracket was developed. Through the collaborative design of a two-axis motion system the robotic arm, a ranging module, and a horizontal calibration unit, the bracketachieves precise positioning of the detector and the standard source, with a positioning deviation of no more than ±0.5 mm, meeting the calibration needs of devices with different detection areas. Test results show that the stability and repeatability of the device are significantly improved, which can reduce personnel radiation exposure time more than 40%, and the annual economic benefit is about 80,000 yuan. This study provides a reliable solution for the metrological calibration radiological pollution detection equipment.