A heat-dissipation system and a matrix thermal sensing circuit are provided. The heat-dissipation is used in an electronic device. The electronic device comprises a circuit board and a plurality of load elements disposed on the circuit board. The matrix thermal sensing circuit includes a current sensing module and a calculation module. The current sensing module includes a plurality of sensing nodes. Each sensing node is electrically connected to a current feeding terminal of one corresponding load element, and senses the working current of the corresponding load element respectively. The calculation module is connected to the current sensing module and is used to determine thermal state of the location of the sensing node according to the working current respectively.