The properties and performance coefficients of thermal storage air conditioning are closely related to the phase change materials. Nano-TiO2 / wax composite emulsion phase change materials （NTWCEPCM） were prepared by using techniques of phase inversion and low energy emulsifying， where the wax and TiO2 nanoparticles were used as dispersion medium and heat carrier， respectively. The effect of nano-TiO2 on the performance of stability，thermal conductivity，and thermal cycling stability of NTWCEPCM was studied. The results show that the thermal conductivity of nano-TiO2 / wax composite emulsion is significantly larger than that of pure wax emulsion; the thermal conductivity of nano-TiO2 / wax composite emulsion increases by 117.95% when the nano-TiO2 particle content is 0.15 %. The phase change platform of nano-TiO2 /wax emulsion in the solid-liquid phase is not obvious during thermal cycling. Moreover，the NTWCEPCM has good thermal cycling stability. The NTWCEPCM is expected to be used in thermal storage air conditioning for improving the performance of thermal storage air conditioning coefficient.