Polyurethane based flexible form-stable phase change materials (PU/APDMS/CNTs) with enhanced thermal conductivity were prepared by one-pot method using polyethylene glycol (PEG10000) and aminopropyl terminated polydimethylsiloxane (APDMS) as soft segments, toluene 2, 4-diisocyanate (TDI) as hard segments, and carbon nanotubes (CNTs) as functional materials. The structural characteristics and thermal properties of the materials were characterized by FTIR, XRD, DSC and TGA. When the content of APDMS is 10 wt%, the enthalpy of phase change of PU/APDMS/CNTs is 88.3 J/g. The PCM does not undergo thermal decomposition at 200℃, and has good thermal stability and figuration performance. The composite phase change material with 5 wt% carbon nanotubes can realize photothermal energy conversion and thermal energy storage with an efficiency is 62.8%. Compared with the phase change material without carbon nanotubes, the thermal conductivity is significantly enhanced and the heating and cooling temperature rate is increased by 2.75 times.