A polarization-modulated fiber-optic sensor with a single sensing head for the simultaneous measurement of two parameters is presented. The possibility of the separation of two parameters from a sensing head is analyzed theoretically. Through optical components arranged properly, the sensing head can simultaneously output two signals which can represents two different physics parameters. The experimental results verify predictions and show that voltage and temperature, or force and temperature can be simultaneously measured by using only one of this kind of sensing head. Under lab condition, when the temperature changes from 20 ℃ to 110 ℃,the force output with the temperature stability of ±0.1% within the range of 0～80 N and the voltage output with temperature staility of ±0.5% within the range of 0～10 kV can be obtained, while the accuracy of the temperature detection is ±1 ℃.