Glide symmetry transmission line (TL) is a highly symmetric TL with characteristics such as reduced frequency dispersion and merged passband. The dispersion characteristics and field distribution of single-layer and double-layer spoof surface plasmon polaritons (SSPPs) unit with glide symmetry are studied in this paper. It is found that the double layer structure with stronger slow wave effect is more suitable for frequency scanning radiation with higher scanning rates. Thus, T-shaped glide symmetric double-layer unit is proposed. Such unit exhibits stronger field confinement and higher degrees of freedom in modulating dispersion characteristics. Besides the basic transmission characteristic, additional radiation characteristic based on such T-shaped glide symmetric double-layer units performs well with continuously beam scanning in a large frequency and angle range. Experimental results agree well with numerical simulations, demonstrating the superior performance of T-shaped glide symmetric double-layer SSPPs. The radiation method of such T-shaped glide symmetric double layer SSPPs can be applied to antenna design, which is conductive to the development of highly compact plasmonic integrated circuits and systems.