Focusing on current Orthogonal Frequency Division Multiplexing(OFDM) communication systems, the integrated waveforms study is conducted based on two-Dimensional Fast Fourier Transform (2D-FFT). The sensing characteristics of THz OFDM waveforms are investigated by combining theoretical analysis with simulations to analyze the impacts of waveform parameter design under various frequencies and bandwidths, aiming to guide the design of THz OFDM Integrated Sensing And Communication(ISAC) systems. Theoretical and simulation analysis demonstrates that the THz OFDM integrated communication and sensing system possesses multi-object sensing capabilities, with the large bandwidth of THz enabling a high range resolution of the OFDM waveform sensing up to the centimeter level and a velocity resolution up to decimeter per second level. Moreover, even under low sensing Signal-to-Noise Ratio(SNR) conditions, the system can still resolve the position and velocity information of targets, confirming the capability of OFDM integrated communication and sensing waveforms to support THz narrow beam mobile communication.