Powerful terahertz (THz) radiation is generated by the interaction between laser and plasma of a super short laser source; such THz radiation is usually single-shot. Herein, we propose a single-shot measurement strategy that involves splitting the THz beam, measuring the THz radiation in the horizontal and vertical directions using two independent spectral detection systems with chirped pulses, and finally obtaining the polarization state. We perform a proof experiment based on this strategy and measure an elliptically polarized THz waveform via the single-shot method. Experimental results agree well with the model analysis, verifying the feasibility of our strategy in addition to providing a new plan for single-shot detection of the polarization state of elliptically polarized THz radiation.