Conventional rotary steerable downhole wireless short transmission is magnetically coupled fixed frequency transmission， The resonant frequency of the communication coil changes with the environment， which easily leading the received signal strength floating with the drilling process， and may not be received in severe cases， and even cause garbled code. In this paper， an adaptive detection technology of downhole communication coil resonance frequency based on automatic window algorithm is proposed. It starts with the introduction of the self-detection principle of downhole communication coil resonance frequency. Then compared with four kinds of adaptive frequency selection algorithms， the automatic window algorithm is determined to be the more reasonable adaptive frequency selection algorithm. Finally， adaptive frequency selection and frequency-sweep method are used to detect the resonant frequency of two batches of customized downhole coils， in order to demonstrate the reliability of automatic window frequency selection technology. This technology can automatically adapt to the downhole environment and provide reliable resonant frequency parameters for downhole wireless short transmission. As the power transmission efficiency of downhole rotary transformer is closely related to the resonant frequency， this technology can also be extended to the deformation design of downhole rotary transformer to optimize the power transmission efficiency during drilling.