Spintronic terahertz (THz) emitter, which is based on ultrafast spin-to-charge current conversion in ferromagnetic/nonmagnetic heterostructures, provides excellent advantages such as ultra-broadband, tunable polarization, and ultra-thin structure, thereby attracting increasing interests recently. In this review article, we first introduce the fundamental concepts of THz wave, THz spintronics and spintronic THz emitter. Next, we focus on the recent progress of spintronic THz emitter by closely looking at the performances, manipulations and applications. Performance improvement is presented based on the three fundamental processes: optical excitation, ultrafast spin transport, and THz emission. The active manipulation of polarization and spectral response, as well as the relevant applications such as ultra broadband measurements, magnetic structure detection and imaging, and THz near-field microscopy, are reviewed comprehensively. Finally, a brief summary and outlook are given.