A flexible circuit board for a circuit breaker comprising: multiple circuit boards, which are hard circuit boards; and flexible connecting members, connected between the independent multiple circuit boards, such that the multiple circuit boards form a circuit board connected by the flexible connecting members, the flexible connecting members being bent such that the multiple circuit boards form a three-dimensional spatial layout, wherein a connection circuit is disposed on the flexible connecting members; the connection circuit connects internal circuits of the multiple circuit boards; the multiple circuit boards comprise: a control circuit board; and a power supply circuit board; an auxiliary function circuit board; characterised in that the flexible connecting members comprise: a first flexible connecting member, two ends of the first flexible connecting member being connected to the control circuit board and the power supply circuit board respectively; a second flexible connecting member, two ends of the second flexible connecting member being connected to the control circuit board and the auxiliary function circuit board respectively; and the three-dimensional spatial layout comprises: the auxiliary function circuit board being disposed between the control circuit board and the power supply circuit board, and being arranged perpendicular to the control circuit board and the power supply circuit board, and the control circuit board and the power supply circuit board being disposed opposite and parallel to each other. multiple circuit boards, which are hard circuit boards; and flexible connecting members, connected between the independent multiple circuit boards, such that the multiple circuit boards form a circuit board connected by the flexible connecting members, the flexible connecting members being bent such that the multiple circuit boards form a three-dimensional spatial layout, wherein a connection circuit is disposed on the flexible connecting members; the connection circuit connects internal circuits of the multiple circuit boards; the multiple circuit boards comprise: a control circuit board; and a power supply circuit board; an auxiliary function circuit board; characterised in that the flexible connecting members comprise: a first flexible connecting member, two ends of the first flexible connecting member being connected to the control circuit board and the power supply circuit board respectively; a second flexible connecting member, two ends of the second flexible connecting member being connected to the control circuit board and the auxiliary function circuit board respectively; and the three-dimensional spatial layout comprises: the auxiliary function circuit board being disposed between the control circuit board and the power supply circuit board, and being arranged perpendicular to the control circuit board and the power supply circuit board, and the control circuit board and the power supply circuit board being disposed opposite and parallel to each other. a control circuit board; and a power supply circuit board; an auxiliary function circuit board; characterised in that the flexible connecting members comprise: a first flexible connecting member, two ends of the first flexible connecting member being connected to the control circuit board and the power supply circuit board respectively; a second flexible connecting member, two ends of the second flexible connecting member being connected to the control circuit board and the auxiliary function circuit board respectively; and the three-dimensional spatial layout comprises: the auxiliary function circuit board being disposed between the control circuit board and the power supply circuit board, and being arranged perpendicular to the control circuit board and the power supply circuit board, and the control circuit board and the power supply circuit board being disposed opposite and parallel to each other.