Rydberg atoms have large electric dipole moments in the microwave and terahertz frequency band. The detection of electromagnetic field intensity in this frequency band can be achieved by using quantum interference effects. Theoretically, this detection method can have a sensitivity much higher than the traditional detection methods. Therefore, electromagnetic field detection and precision measurement technology based on Rydberg atomic quantum effects has great application prospects in terahertz field strength and power measurement, terahertz communication and imaging. In this paper, we review the basic theory and experimental methods to realize the self-calibration and traceability measurement of electromagnetic field based on Rydberg atomic quantum effects. The principle and technical scheme of high-sensitivity terahertz field strength measurement, terahertz near-field high-speed imaging and terahertz digital communication based on Rydberg atom are introduced in detail. Finally, the processing terahertz detection work based on Rydberg atom by our research team is also mentioned briefly.