The　solar　-driven　calcium　looping　is　a　very　promising　high　-temperature　thermochemical　energy　storage　technology.　The　calcium　-based　particles　suffers　from　high　thermal　stress　and　is　prone　to　fragmentation　in　high　-flux　concentrated　solar　power　systems.　Therefore,　in　this　study,　calcium　carbonate　spherical　particles　with　certain　hardness　were　prepared　using　the　extrusion　spheronization　method,　and　the　real　pore　structure　of　calcium　carbonate　particles　was　obtained　through　micro　-computed　tomography　scanning　(　mu-CT).　Next,　the　displacement　and　strain　of　the　calcium　carbonate　particles　during　the　heating　process　were　measured　in　real-time　using　optical　methods.　Integration　of　displacement　vectors　in　different　directions　showed　that　the　displacement　in　the　X　direction　was　the　dominant　direction.　Subsequently,　numerical　simulation　was　employed　to　calculate　the　temperature　field　and　stress　field　of　the　calcium　carbonate　particles　with　the　real　pore　structure.　The　results　showed　that　with　the　increase　of　heating　time,　the　maximum　temperature　difference　within　the　particles　increased　from　6　K　to　13　K,　and　the　corresponding　maximum　thermal　stress　on　the　particles　increased　from　2.13　MPa　to　3.87　MPa.　Finally,　the　maximum　thermal　stress　obtained　from　numerical　simulations　was　compared　with　experimental　results,　and　the　results　showed　good　agreement　between　the　experimental　and　simulated　values,　with　an　error　range　of　8.93　%　-　21.64　%　and　an　average　error　of　16.9　%.　The　findings　are　of　significant　importance　for　preventing　the　fracture　of　high　-temperature　thermochemical　energy　storage　particles　during　operation.