Accurate placement of the needle is critical in percutaneous surgery. Needle shape reconstruction technology based on fiber Bragg gratings (FBGs) sensor is considered to have the potential to achieve this goal. In this paper, we present a temperature-insensitive calibration model for calibrating needles with FBG sensors to accurately estimate its deformation. In addition, we have designed a device for simultaneously calibrating the loading direction and shape. Preliminary results indicate that the proposed model is theoretically insensitive to temperature, but in fact it can only be used within a certain temperature range. The resolution of the loading direction increases as the degree of bending increases, with a maximum error of 8.58°. Shape reconstruction error can be less than 1.5mm with small needle bending. This calibration method can meet clinical applications.