Abstract: Ultrasonic puncture navigation plays an increasingly important role in tissue biopsy and surgical guidance. In this paper, high-precision electromagnetic locators were used to track ultrasound probes and puncture needles in real time, and real-time tracking software for puncture guidance was developed. Firstly, a NDI Aurora electromagnetic locator was used to acquire the three-dimensional coordinates of the puncture needle tip in real time, and the PLUS toolkit was used to acquire data from the electromagnetic locator and the ultrasound machine based on the completion time and spatial calibration (tip calibration, phantom calibration, and probe calibration).Then a conversion matrix was designed for the information got from the electromagnetic positioning coordinate system to the ultrasonic image coordinate system, and the position of the needle tip was converted into an ultrasonic image. Finally, to measure the accuracy of the algorithm, the coordinates of the needle tip in the image were manually selected, multiply samples were averaged, and the coordinate was taken as the standard of measurement. Multiple sets of data were collected and the mean square error (MSE) was calculated for the tip coordinates obtained from the transformation matrix and the standard coordinates. The results, for example MSE 2.456 mm, all are within the acceptable range.