A Novel passive wireless surface acoustic wave (SAW) temperature sensor is presented in this paper. The sensor energy comes from the wireless electromagnetic waves at the outside world. A multistrip coupler and two reflectors located different tracks are used.The former can eliminate the disturbance from bulk acoustic wave (BAW), while the latter can improve the accuracy of the temperature measurement by introducing a delay between the two SAW propagation tracks. In addition, the IDT with wavelet envelope weight is used to suppress the sidelobe of the frequency response curve and improve the quality factor. Meanwhile, the transducer structure with the singleended input and singleended output is also used to reduce the size of the sensor effectively and enlarge the applying scope.