A paper sheet handling apparatus (50, 50a), comprising: a paper sheet handling module to handle and convey a paper sheet; and a plurality of storage modules (100, 200) sequentially connected to the paper sheet handling module, wherein each of the storage modules (100, 200) comprises: a paper sheet storage cassette (102, 202) to store the paper sheet; a holding module (104, 204) holding the paper sheet storage cassette (102, 202), wherein the holding module (104, 204) of each of the storage modules (100, 200) is detachably connected to the holding module (104, 204) of at least adjacent one of the storage modules (100, 200); and a conveyance assembly (106, 206) detachably connected to the holding module (104, 204), wherein the paper sheet storage cassette (102, 202) and the paper sheet handling module are located at two opposite sides of the conveyance assembly (106, 206) respectively, and the conveyance assembly (106, 206) is adapted to convey the paper sheet between the paper sheet storage cassette (102, 202) and the paper sheet handling module, wherein the number of the storage modules (100, 200) is changeable for use with another paper sheet handling module, wherein each of the conveyance assemblies (106, 206) has two connecting ends (106a, 206a) opposite to each other, at least one of the connecting ends (106a, 206a) of each of the conveyance assemblies (106, 206) is adjacent to at least one of the connecting ends (106a, 206a) of at least another one of the conveyance assemblies (106, 206), wherein all the conveyance assemblies (106,206) have the same size, and the conveyance assemblies (106, 206) are each detachably connected to each other by the connecting ends (106a, 206a). a paper sheet handling module to handle and convey a paper sheet; and a plurality of storage modules (100, 200) sequentially connected to the paper sheet handling module, wherein each of the storage modules (100, 200) comprises: a paper sheet storage cassette (102, 202) to store the paper sheet; a holding module (104, 204) holding the paper sheet storage cassette (102, 202), wherein the holding module (104, 204) of each of the storage modules (100, 200) is detachably connected to the holding module (104, 204) of at least adjacent one of the storage modules (100, 200); and a conveyance assembly (106, 206) detachably connected to the holding module (104, 204), wherein the paper sheet storage cassette (102, 202) and the paper sheet handling module are located at two opposite sides of the conveyance assembly (106, 206) respectively, and the conveyance assembly (106, 206) is adapted to convey the paper sheet between the paper sheet storage cassette (102, 202) and the paper sheet handling module, wherein the number of the storage modules (100, 200) is changeable for use with another paper sheet handling module, wherein each of the conveyance assemblies (106, 206) has two connecting ends (106a, 206a) opposite to each other, at least one of the connecting ends (106a, 206a) of each of the conveyance assemblies (106, 206) is adjacent to at least one of the connecting ends (106a, 206a) of at least another one of the conveyance assemblies (106, 206), wherein all the conveyance assemblies (106,206) have the same size, and the conveyance assemblies (106, 206) are each detachably connected to each other by the connecting ends (106a, 206a). a paper sheet storage cassette (102, 202) to store the paper sheet; a holding module (104, 204) holding the paper sheet storage cassette (102, 202), wherein the holding module (104, 204) of each of the storage modules (100, 200) is detachably connected to the holding module (104, 204) of at least adjacent one of the storage modules (100, 200); and a conveyance assembly (106, 206) detachably connected to the holding module (104, 204), wherein the paper sheet storage cassette (102, 202) and the paper sheet handling module are located at two opposite sides of the conveyance assembly (106, 206) respectively, and the conveyance assembly (106, 206) is adapted to convey the paper sheet between the paper sheet storage cassette (102, 202) and the paper sheet handling module, wherein the number of the storage modules (100, 200) is changeable for use with another paper sheet handling module, wherein each of the conveyance assemblies (106, 206) has two connecting ends (106a, 206a) opposite to each other, at least one of the connecting ends (106a, 206a) of each of the conveyance assemblies (106, 206) is adjacent to at least one of the connecting ends (106a, 206a) of at least another one of the conveyance assemblies (106, 206), wherein all the conveyance assemblies (106,206) have the same size, and the conveyance assemblies (106, 206) are each detachably connected to each other by the connecting ends (106a, 206a).