Aiming at some problems of existing optical fiber voltage sensors, such as complex structure, adjustment difficulties, poor temperature stability, optical power loss and voltage introduced inconvenience, a new structure of suspended optical fiber voltage sensor based on all polarization state detection without polarizer and analyzer was proposed. The sensor only contained three main elements that are a selffocusing lens, a Bi4Ge3O12 crystal and a total reflection mirror.For the fewer devices,the structrue is simple and it is easy to align. All polarization state detection system was described. It uses divisionofamplitude method and has fast response and simple algorithm.Formulas about polarization state, electric field and the measured voltage were calculated.Experiment of measuring the high voltage by suspending the sensor was demonstrated. The sensor in the experiment has no electrode and without ground,which eliminates the need for expensive insulators and increases the range of the sensor. The experiment results show that the sensor has a good linearity at room temperature in the range of 0~10 kV AC voltage at powerfrequency,which proves the feasibility of the structure.