A rotary shaft apparatus, comprising: a base plate ; and a rotary shaft assembly , comprising a first transmission assembly , a second transmission assembly and a first supporting member ; the first transmission assembly is rotatably connected to the base plate around a first axial direction; the first supporting member is rotatably connected to the first transmission assembly around a second axial direction parallel to the first axial direction, and is movably connected to the second transmission assembly ; and the second transmission assembly is rotatably connected to the base plate around a third axial direction parallel to the first axial direction; characterized in that , the rotary shaft apparatus further comprises a second supporting member movably arranged on the base plate in a direction perpendicular to the first axial direction; the base plate comprises a first supporting plane , the first supporting member comprises a second supporting plane , and the second supporting member comprises a third supporting plane ; the rotary shaft apparatus has an unfolded state and a folded state; in the unfolded state, the second supporting member is at a first position, and the third supporting plane and the second supporting plane are on the same plane; in the folded state, a first preset included angle is between the second supporting plane and the first supporting plane , the second supporting member is at a second position, and the second position is closer to the base plate than the first position; and the first supporting member and the second supporting member define a screen-accommodating space. a base plate ; and a rotary shaft assembly , comprising a first transmission assembly , a second transmission assembly and a first supporting member ; the first transmission assembly is rotatably connected to the base plate around a first axial direction; the first supporting member is rotatably connected to the first transmission assembly around a second axial direction parallel to the first axial direction, and is movably connected to the second transmission assembly ; and the second transmission assembly is rotatably connected to the base plate around a third axial direction parallel to the first axial direction; characterized in that , the rotary shaft apparatus further comprises a second supporting member movably arranged on the base plate in a direction perpendicular to the first axial direction; the base plate comprises a first supporting plane , the first supporting member comprises a second supporting plane , and the second supporting member comprises a third supporting plane ; the rotary shaft apparatus has an unfolded state and a folded state; in the unfolded state, the second supporting member is at a first position, and the third supporting plane and the second supporting plane are on the same plane; in the folded state, a first preset included angle is between the second supporting plane and the first supporting plane , the second supporting member is at a second position, and the second position is closer to the base plate than the first position; and the first supporting member and the second supporting member define a screen-accommodating space. <EOS>