Considering the shortcomings of contact thermometer, such as low precision, poor real-time performance and cross-infection, a body temperature implantable sensor of cow was developed to realize the intelligent detection of cow body temperature signal by using wireless sensor network. PT1000 was used as temperature measuring probe, and the analog-to-digital converter ADS1256 and control chip MSP430 were used to filter the acquisition voltage and improve the accuracy. The 433M wireless signal module was used in conjunction with the ZigBee network to design the collar node, as a relay node that transmitted cow body temperature data from body to outside. In details, the 433M wireless signal was transmitted from cow to collar node, then the 2.4GHz ZigBee network was used from collar node to remote monitoring center, which worked more stable and reliable, realizing high-precision real-time monitoring of temperature. The sensor accuracy, stability, reaction speed, transmission performance and system packet loss rate were tested, respectively. The results showed that the designed sensor temperature measurement error was less than 0.05℃, the maximum fluctuation of 12h temperature measurement was 0.02℃, which was stable within 15s. The information can be effectively transmitted to the collar node by using implantable sensor RF. Inside one cattle farm, the packet loss rate of the whole system was no more than 1.2%, providing important data for cow estrous prediction and disease prevention. Vaginal temperature could become a good indicator for predicting not only the onset of calving, but also the necessity of assistance. The research result can also be a reference for other animals’ temperature detection.