In this work, we propose a novel Si-compatible resonant plasma-wave transistor (R-PWT) with 2D silicene channel for a high-performance terahertz (THz) electromagnetic (EM) wave emitter. High resonance quality i.e. narrow emission spectra can be obtained by high mobility of 2D silicene channel (μ= 2×105 cm2V−1·s−1) since nanoscale channel length L can be much smaller than the maximum channel length Lmax= 1395 nm even under relatively low gate voltage.