Abstract: Carbon nanotube films (CNTF) can be prepared by the chemical vapor deposition (CVD) method over a large area. However, CNTF prepared by this method typically contain a significant amount of carbon-coated iron nanoparticles. These impurities greatly increase carrier transport resistance, hindering the full realization of the thermoelectric potential of CNTF. In this study, a process combining stepwise calcination and reaction with dilute hydrochloric acid was adopted to remove iron impurities and purify the CNTF, which can optimize carrier transport channels. Following this treatment, the purified CNTFs achieved a high electrical conductivity (1 196 S/cm) and a power factor (311 μW/mK²). Thermoelectric device units prepared based on these purified CNTF demonstrated excellent thermoelectric performance, reaching a specific mass output power of 633.913 μW/g. This work provides an effective strategy for enhancing the thermoelectric properties of flexible carbon nanotube-based materials.