Abstract: A micro-nano channel structure, a method for manufacturing the micro-nano channel structure, a sensor, a method for manufacturing the sensor, and a microfluidic device are provided by the embodiments of the present disclosure. The micro-nano channel structure includes: a base substrate; a base layer, on the base substrate and including a plurality of protrusions; and a channel wall layer, on a side of the plurality of the protrusions away from the base substrate, and the channel wall layer has a micro-nano channel; a recessed portion is provided between adjacent protrusions of the plurality of the protrusions, and an orthographic projection of the micro-nano channel on the base substrate is located within an orthographic projection of the recessed portion on the base substrate.