Abstract: The time-frequency electromagnetic method (TFEM) represents an artificial-source electromagnetic survey technology developed by integrating the advantages of both the frequency-domain controlled-source electromagnetic (FD-CSEM) method and the transient electromagnetic (TEM) method. This technology enables simultaneous acquisition of time-domain and frequency-domain electromagnetic responses with a single excitation. It is characterized by large exploration depths, multi-parameter inversion, high signal-to-noise ratio, and strong anti-interference capability, providing technical support for the fine characterization of subsurface structures. This study presents a systematic review of the TEFM, covering its core technical architecture and the equipment development roadmaps in China and abroad, with a particular emphasis on the analysis of the theoretical models, application status, and technical bottlenecks of the TFEM in three major fields, i.e., hydrocarbon exploration, mineral exploration, and geothermal resource surveys. The results of this study indicate that the TFEM effectively overcomes the limitations of traditional electromagnetic methods in exploration depth and parameter dimensionality, thus fully satisfying the high-precision and large-depth requirements of current energy resource exploration. However, its application in mineral and geothermal fields is in a critical stage of large-scale expansion, with its potential yet to be fully tapped. In the future, the TFEM technology will be expanded into fields such as ground-air collaborative detection and 3D/4D time-lapse monitoring, accompanied by constant innovations in multi-physics coupling and intelligent inversion algorithms. These advances will provide new impetus for its industrial application and technological upgrade.