Due　to　the　deficiencies　of　the　existing　score　function　in　Pythagorean　fuzzy　sets,　a　novel　score　function　is　proposed,　and　the　relevant　theorems　are　proved　to　analyze　the　properties　of　the　novel　score　function.　Then,　the　novel　score　function　is　introduced　to　Pythagorean　fuzzy　multi-attribute　decision　making　methods　to　help　decision　makers　(DM)　process　the　fuzzy　decision　information.　Additionally,　most　Pythagorean　fuzzy　decision　methods　are　based　on　the　expected　utility　theory,　which　assumes　that　the　DM　has　perfect　knowledge　about　the　decision　environment　associated　with　perfectly　rational　when　making　decisions,　and　the　subjective　value　perception　of　the　DM　is　ignored　when　facing　losses　and　gains.　Therefore,　the　cumulative　prospect　theory　is　introduced　to　reflect　the　subjective　value　perception　of　the　DM　and　the　prospect　values　are　used　to　replace　the　distance　measure　between　alternatives　and　ideal　solution　for　avoiding　the　effects　of　correlation　between　different　attributes,　then　the　Pythagorean　fuzzy　TOPSIS　method　based　on　the　novel　score　function　and　the　cumulative　prospect　theory　is　proposed,　where　the　attribute　weights　are　known　and　attribute　values　are　in　the　form　of　Pythagorean　fuzzy　number　(PFN),　and　the　weights　of　attributes　are　determined　by　the　contributing　degree　of　the　grey　target　theory.　Finally,　an　example　is　given　to　illustrate　the　validity　of　the　proposed　score　function,　and　then　several　sets　of　simulation　data　are　used　to　verify　the　effectiveness　and　feasibility　of　the　proposed　method.　Copyright　©2022　Control　and　Decision.