Highly conducting carbon nanotubes (CNTs)/polydimethylsiloxane (PDMS) composite with a low concentration (5.7 vol.%) has been shown to be applicable in a highly controllable electric heating element. Due to a high shear-processing technique for mixing CNTs into an uncured PDMS matrix, the CNT/PDMS composites have a fairly uniform dispersion and no agglomeration of CNTs. The percolation threshold of the prepared CNT/PDMS composite is achieved , which is one of the lowest values previously reported in the literature. The fabricated CNT/PDMS composites can be quickly heated from room temperature to 200 within 30 s by applying a DC voltage of 12 V. In addition, the CNT/PDMS composite show good thermal stability and repeatability during a long-term heating test. Our proposed CNT/PDMS composites could be used as a basis for light-weight and flexible heating-unit applications.