Graphene-based composite phase change materials (CPCMs) have great potential for energy storage applications due to their excellent loading capacities and thermal conductivity, their ability to store PCMs and suppress liquid leakage during phase change. However, there are few graphene-based CPCMs capable of storing low-temperature industrial waste heat. In this paper, 1-hexadecylamine (HDA) was selected as the PCMs and 3D graphene aerogel (GA) was used as the support material to prepare HDA/GA CPCMs by melt impregnation method. The results show that the HDA is uniformLy distributed in the GA, and the HDA/GA CPCMs with high latent heat and high thermal conductivity were obtained. The melting temperature was 56.8 °C and the solidification temperature was 55.0 °C, and the latent heat was as high as 284.5 kJ/kg, which was 1.05 times higher than that of pure HDA, and the sub-cooling degree was in the range of 4–10 °C. The thermal conductivity of the HDA/GA at 25 °C was 0.238 W/(m·K), which was 1.61 times higher than the thermal conductivity of the HDA, and the loading of the GA on the HDA was up to 5600%. The above results indicate that HDA/GA CPCMs have promising applications in low-temperature energy storage. •HDA/GA composite phase change material suitable for storage of low temperature industrial waste heat.•The latent heat of HDA/GA-1 reaches 284.5 kJ/kg, which was 1.05 times than that of HDA.•The thermal conductivity of 3D graphene aerogel is 0.238 W/(m·K), which is 1.61 times than that of HDA.