Nowadays, the BJT-based temperature sensors have occupied the majority of the market. Due to process spread, BJT-based temperature sensors usually requires calibration. Currently, thermal calibration is the only method. However, it is usually costly and time consuming. In this paper, a new calibration method called voltage calibration is proposed. Compared to thermal calibration, voltage calibration is more convenient to apply and financially saving. Meanwhile, it can offer similar accuracy as thermal calibration.