The　purpose　of　this　investigation　is　to　find　and　prepare　novel　heat　storage　materials　to　meet　the　requirement　of　Concentrating　Solar　Power　(CSP)　system.　This　paper　focuses　on　the　formulation,　fabrication　and　characterization　of　a　novel　molten　salt　nanocomposite　for　high-temperature　heat　energy　storage.　The　molten　salt　nanocomposite　is　based　on　eutectic　quaternary　salt,　and　two　different　concentrations　of　SiO2　and　TiO2　nanoparticles　are　added　to　improve　its　specific　heat　capacity　and　thermal　conductivity　by　microwave　method.　Concerning　the　material　characterization,　a　suite　of　techniques　was　used,　including　simultaneous　thermal　analysis　(STA)　and　laser　flash　analysis　(LFA).　The　consequences　demonstrate　that　the　melting　point　and　latent　heat　of　molten　salt　nano　composites　can　be　reduced　by　adding　two　different　concentrations　of　nanoparticles　at　the　same　time.　The　specific　heat　is　28.1%　higher　than　that　of　the　pure　quaternary　salt,　and　6.3%　and　9.8%　higher　than　that　of　adding　SiO2　and　TiO2　nanoparticles　separately　when　adding　0.1　wt%　SiO2　and　0.9　wt%　TiO2　nanoparticles　to　the　quaternary　nitrate.　Compared　with　pure　quaternary　salt,　the　thermal　conductivity　of　the　molten　salt　nanocomposites　increased　by　53.7%,　which　was　16.8%　and　6.3%　higher　than　that　of　adding　SiO2　and　TiO2　nanoparticles　separately.　Upon　inspection　with　scanning　electron　microscopy,　a　high-density　nanostructure　and　heat　transfer　channel　were　observed,　which　appear　to　be　the　reason　for　the　enhancement　of　specific　heat　and　thermal　conductivity　of　the　material.　Finally,　the　molten　salt　nanocomposite　has　a　broad　application　prospects　in　high　temperature　thermal　storage　system.