The innovative form-stable phase change materials (PCMs) were fabricated by incorporating capric-myristic-stearic acid (CMS) ternary eutectic mixture with cellulose acetate (CA) phase inversion membrane. CMS as model PCM, with melting point near ambient temperature as the temperature range was most valuable in practice. Effects of different SiO₂ amounts on surface features, structural morphology and absorption capacity of CA membrane were investigated. The SiO₂ nanoparticles created porous structure and increased CMS incorporation capability of CA membrane, the maximum absorption capacity of CA-SiO₂ membrane was ∼80.3 wt.%. The enthalpies of melting of form-stable PCMs were 76.6 kJ/kg for CA membrane and 99.8 kJ/kg for CA-SiO₂ membrane, respectively. The SiO₂ nanoparticles increased remarkably thermal stability property of form-stable PCMs. As compared to CA-SiO₂ membrane, the control temperature time of CMS/CA-SiO₂ form-stable PCMs was increased by ∼46.8%. The developed form-stable PCMs demonstrated good thermal storage/retrieval property and thermal insulation capability.