A strain sensing device and a manufacturing method thereof are provided in the invention. The strain sensing device includes a substrate and at least one sensing electrode. The substrate has a plurality of pores. A material of the substrate includes nanocellulose, and the substrates is strained in response to changes in external conditions. The at least one sensing electrode is disposed on the substrate, wherein the sensing electrode contacting the substrate extends into the pores of the substrate. The at least one sensing electrode has a major axis parallel to a surface of the substrate. A resistance value of the at least one sensing electrode changes in response to a strain of the substrate.