Aerogel fibers, which are beneficial for enhancing the thermal response and preventing the leakage of phase-changeable materials (PCMs) during phase change process, are excellent candidates for phase-changeable textiles with excellent thermoregulating performance. Herein, polyimide/boron nitride (PI-BN) composite aerogel fibers with highly porous structure and good mechanical strength have been prepared by freeze-spinning technique, which could be served as the heat conduction path and skeleton for PCMs. Into the pores of the PI-BN aerogel textile was incorporated polyethylene glycol (PEG) by vacuum impregnation to obtain phase-changeable PI-BN/PEG textile. The high thermal conductivity of PI-BN skeleton could endow the quick thermal response rate of PI-BN/PEG textile upon the phase change process, while the high porosity of aerogel fiber could allow high loading of PEG and inhibit liquid leakage during phase change process. The resultant PI-BN/PEG composite textile has high thermal conductivity (5.34 W m−1 K−1), high enthalpy (125.2 J g−1) and excellent work stability after 100 heating-cooling cycles, accounting for the desired thermoregulating performance. Moreover, polydimethylsiloxane (PDMS) has been coated on the surface of PI-BN/PEG textile, endowing the textile hydrophobicity, waterproofness and washability, indicating its great potential as candidate for personal thermal management.