This paper presents a new method about monitoring the deformation of the tower by monitoring the spatial position of certain nodes of the tower. First of all, we need to install the different frequency RFID tags on different nodes, and install CPCI203 in different reference points of the ground to receive carrier signals. Since carrier signals are different at different reference points, we can use the phase differences between these receiving points to find out the distance differences between the tags and the reference points. We can use the three independent distance equations to solve a tag XYZ coordinates. Finally, we can determine the tower deformation of position and size by comparing the calculated coordinates of the tag with its actual coordinates. Some experiments show that this system can monitor the deformation of five centimeters.