A stress detection device includes: a first detector including a first magnetostrictive member configured to be deformed by tensile stress or compression stress in accordance with a load from outside, and a first wound portion made of a conductive material and configured to be wound around the first magnetostrictive member; and a second detector including a second magnetostrictive member having a magnetostrictive constant different from a magnetostrictive constant of the first magnetostrictive member, the second magnetostrictive member being configured to be deformed by tensile stress or compression stress in accordance with a load from outside, and a second wound portion made of a conductive material and configured to be wound around the second magnetostrictive member, wherein the first detector and the second detector are configured to electrically detect strength of magnetic permeability due to compression stress or tensile stress, and output detection signals having opposite signals.