A flow path switching valve comprising: a main valve housing defining a main valve chamber; and a slide-type main valve body arranged movably in an axial direction and in the main valve chamber, wherein: the main valve chamber has three ports (pA, pB, pF) opened and aligned in the axial direction and has other three ports (pB, pC, pD) opened and aligned in the axial direction at the opposite side to the three ports (pA, pB, pF) across an axis, and the ports communicated with each other are switched by moving the main valve body inside the main valve chamber, the main valve body has a tubular high-pressure side slide valve body and a low-pressure side valve body freely slidably fit to an inner side of the high-pressure side slide valve body, a bridge, which connects inner circumferential surfaces of the high-pressure side slide valve body facing each other in a direction orthogonal to the axial direction, is provided on the inner circumferential surfaces, a convex portion protruding toward a high-pressure side slide valve body-side is provided in the low-pressure side slide valve body, characterized in that a high-pressure side U-turn path to which fluid with high pressure is introduced is defined in a space surrounded by the convex portion and the inner circumferential surface of the high-pressure side slide valve body, a curved portion having a dome-shape in cross section which is curved and protruding toward the low-pressure side slide valve body is formed in the bridge. a main valve housing defining a main valve chamber; and a slide-type main valve body arranged movably in an axial direction and in the main valve chamber, wherein: the main valve chamber has three ports (pA, pB, pF) opened and aligned in the axial direction and has other three ports (pB, pC, pD) opened and aligned in the axial direction at the opposite side to the three ports (pA, pB, pF) across an axis, and the ports communicated with each other are switched by moving the main valve body inside the main valve chamber, the main valve body has a tubular high-pressure side slide valve body and a low-pressure side valve body freely slidably fit to an inner side of the high-pressure side slide valve body, a bridge, which connects inner circumferential surfaces of the high-pressure side slide valve body facing each other in a direction orthogonal to the axial direction, is provided on the inner circumferential surfaces, a convex portion protruding toward a high-pressure side slide valve body-side is provided in the low-pressure side slide valve body, characterized in that a high-pressure side U-turn path to which fluid with high pressure is introduced is defined in a space surrounded by the convex portion and the inner circumferential surface of the high-pressure side slide valve body, a curved portion having a dome-shape in cross section which is curved and protruding toward the low-pressure side slide valve body is formed in the bridge. the main valve chamber has three ports (pA, pB, pF) opened and aligned in the axial direction and has other three ports (pB, pC, pD) opened and aligned in the axial direction at the opposite side to the three ports (pA, pB, pF) across an axis, and the ports communicated with each other are switched by moving the main valve body inside the main valve chamber, the main valve body has a tubular high-pressure side slide valve body and a low-pressure side valve body freely slidably fit to an inner side of the high-pressure side slide valve body, a bridge, which connects inner circumferential surfaces of the high-pressure side slide valve body facing each other in a direction orthogonal to the axial direction, is provided on the inner circumferential surfaces, a convex portion protruding toward a high-pressure side slide valve body-side is provided in the low-pressure side slide valve body, characterized in that a high-pressure side U-turn path to which fluid with high pressure is introduced is defined in a space surrounded by the convex portion and the inner circumferential surface of the high-pressure side slide valve body, a curved portion having a dome-shape in cross section which is curved and protruding toward the low-pressure side slide valve body is formed in the bridge.