The invention discloses a flexible splicing type aluminum substrate with high thermal conductivity, and belongs to the technical field of aluminum substrates. Flexible butt joint between a pair of aluminum substrates is realized by utilizing a flexible connection part, so that two adjacent aluminum substrates can be conveniently mounted in a relatively narrow space, positioning and heat conduction effects are achieved, and when a heat dissipation seat is subjected to heat conduction, the heat expansion part pushes a magnetic plate to press downwards after being heated, negative pressure is formed in the heat dissipation seat after the magnetic plate is pressed downwards, hot air at the position of the circuit layer is easily guided into the heat dissipation seate through the flexible connection part and then overflows from the multiple one-way air valve ports, air circulation at the position of the aluminum substrate is intensified, and the heat conduction performance is improved.In addition, after the magnetic plate is pressed downwards, a deformation bearing is pushed to stretch so as to trigger the deformation bearing to repel the magnetic plate, the magnetic plate retreats upwards after being magnetically repelled, the deformation bearing elastically recovers to the initial state, and the magnetic plate is continuously heated to expand and downwards press in a high-temperature environment, so that the up-and-down reciprocating circulating motion of the magnetic plate is realized, and high-temperature gas is continuously emitted outwards.