When measuring the physical vectors in engineering such as underwater target's magnetic and electric fileds, the attitude angle of the measurement sensor is usually arbitrary or random, so the attitude angle of the sensor platform needs to be measured, thereby the measured data of the physical vector are corrected to the determined reference coordinate system. In this pa- per, the correcting algorithm commonly used in the literature is analyzed, that is, the Euler angle rotation transformation formula is directly quoted according to the measured value of the attitude angle of sensor platform. The analysis shows that there is a principle error in this algorithm. On this basis, a reasonable transformation formula is deduced, which can be applied directly in the correcting algorithm of measured data of the physical vector in arbitary attitude and similar coordinate transformation calculation.