A novel type fiber optic measuring system of high accuracy was successfully manufactured and the in situ one-time measurement was realized with an electrionics-free sensor head. A new balanced bridge referencing compensation technique was introduced so that the sensor was immune to various adverse effects and had higher measurement accuracy. According to practical needs, the measurement ranse of pressure from 0 up to 147.10 kpa was determined. The measurement accuracy is 0. 2%. Error was analyzed in detail and corresponding methods to reduce the measurement error were given.