Abstract: Sensor units of marine power plant are subject to either change of inherent characteristics or functional failure under adverse working conditions.This paper presents a new approach to building up testing calibration shelter for sensor units in a large-sized maintenance repair ship for purpose of maintenance and logistic support.According to the features of sensor units and the loading conditions on board the ship,basic requiremen ts for maintenance by the shelter are put forward.The general design scheme is given and the preliminary design scheme of key component,known as sensor calibration test board for testing pressure,thermal and liquid lev el etc,are presented.The results may be used as guide for preliminary design of similar shelter onboard the ship.