One　of　the　key　challenges　in　the　development　of　high-temperature　energy　harvesting　(HTEH)　technology　is　to　clarify　the　relationship　between　temperature-dependent　material　parameters　and　device　power　generation　capabilities.　However,　at　present,　the　research　on　temperature　stability　of　piezoceramics　mainly　relies　on　thermal　annealing　technology,　which　cannot　follow　the　actual　temperature　dependence　of　the　piezoelectricity,　and　it　is　even　more　difficult　to　predict　the　temperature　stability　of　HTEH.　To　shed　light　on　this　field,　here,　(1-x)BiScO3-xPbTiO(3)　system　was　chosen　for　building　HTEH　material,　and　the　temperature-dependent　electrical　parameters,　such　as　d(33),　epsilon(r),　and　g(33),　have　been　measured　by　multiple　in　situ　techniques.　It　was　found　that　the　synergistic　effect　of　d(33)　and　epsilon(r)　with　temperature　helps　to　obtain　a　stable　g(33)　value　in　a　wide　temperature　range.　Moreover,　in　the　mode　of　the　cantilever-type　energy　harvester,　a　stable　output　voltage　was　obtained　at　x=0.64　harvester　with　＜20%　change　over　a　broad　temperature　range　of　100-250　degrees　C,　and　it　was　verified　that　the　temperature　stability　of　g(33)　is　crucial　to　the　operation　stability　of　HTEH　devices.