The precision of piezoresistive sensors is low between wide temperature range .The conditioning result isn’t ideal by analog approaches. Also the efficiency is very low. To improve this condition , a digital approach is introduced. It coverts sensors’ analog signal to digital value, and then uses polynomial and coefficients stored in singlechip to correct the digital value. At last , the singlechip coverts corrected digital value to analog signal to output. Its conditioning principle and calibration process is also described. We realized 4-to-20mA-current-loop-output of piezoresistive sensors using this aprroch. Calibration results show this method is efficient and low cost.