Considering the structural characteristics of space one-dimensional deployable truss,a precision measurement method for the space one-dimensional deployable truss structure is presented.The measurement method is based on spot center position detection principle of quadrant detector,and collimated laser beam is used as Measuring Datum.Using this method,the torsional angle,lateral deviation,vertical deviation of each truss bay in the truss and the truss straightness can been measured.Two-dimensional plane calibration method of the quadrant detector is presented,and working range of the quadrant detector is enlarged to 3 mm×3 mm,measuring accuracy of the quadrant detector is improved to 0.05 mm.Precision of the space one-dimensional deployable truss is measured based on quadrant detector.The maximal torsional angle of the truss bay is measured to be 0.133 3°,the maximal lateral deviation and vertical deviation of the truss bay are 1.200 8 mm and 1.099 3 mm respectively,and the truss straightness is measured to be 1.090 6 mm.The precision measurement test of the space one-dimensional deployable truss verifies the effectiveness of the method presented.