A microwave drying device, characterized in that the microwave drying device comprises: a processing box being hollow and having: two external conveying walls disposed apart from each other along a conveying direction; each one of the external conveying walls having a box conveying opening; an external mounting wall connected between the two external conveying walls and having two mounting openings; the two mounting openings disposed apart from each other along the conveying direction; an external sealing wall connected between the two external conveying walls; the external mounting wall and the external sealing wall located on two opposite sides of the processing box respectively; at least one suction partition mounted in the processing box to divide an inner space of the processing box into a microwave drying space and at least one suction space; multiple suction holes formed through the at least one suction partition; and multiple channel partitions mounted in the microwave drying space; the channel partitions disposed apart from each other along the conveying direction to form a wave travelling channel meandering and extending back and forth repeatedly in the microwave drying space; two opposite ends of the wave travelling channel connecting to the two mounting openings respectively; the suction holes of the at least one suction partition connecting to the at least one suction space and the wave travelling channel; each one of the channel partitions having: a partition conveying opening; the partition conveying openings of the channel partitions and the two box conveying openings of the two external conveying walls being aligned; at least one suction module connecting to the at least one suction space; and at least one microwave emitting module mounted on the external mounting wall of the processing box and emitting microwaves toward the wave travelling channel. two external conveying walls disposed apart from each other along a conveying direction; each one of the external conveying walls having a box conveying opening; an external mounting wall connected between the two external conveying walls and having two mounting openings; the two mounting openings disposed apart from each other along the conveying direction; an external sealing wall connected between the two external conveying walls; the external mounting wall and the external sealing wall located on two opposite sides of the processing box respectively; at least one suction partition mounted in the processing box to divide an inner space of the processing box into a microwave drying space and at least one suction space; multiple suction holes formed through the at least one suction partition; and multiple channel partitions mounted in the microwave drying space; the channel partitions disposed apart from each other along the conveying direction to form a wave travelling channel meandering and extending back and forth repeatedly in the microwave drying space; two opposite ends of the wave travelling channel connecting to the two mounting openings respectively; the suction holes of the at least one suction partition connecting to the at least one suction space and the wave travelling channel; each one of the channel partitions having: a partition conveying opening; the partition conveying openings of the channel partitions and the two box conveying openings of the two external conveying walls being aligned; at least one suction module connecting to the at least one suction space; and at least one microwave emitting module mounted on the external mounting wall of the processing box and emitting microwaves toward the wave travelling channel. a partition conveying opening; the partition conveying openings of the channel partitions and the two box conveying openings of the two external conveying walls being aligned; at least one suction module connecting to the at least one suction space; and at least one microwave emitting module mounted on the external mounting wall of the processing box and emitting microwaves toward the wave travelling channel.