A slide detent device includes a second slide member slidably connected to a first slide member, and a stop member secured to the first slide member. A third slide member slidably connected to the second slide member includes a pair of third margins walls defining a pair of sliding raceways. The stop member includes a pair of extension wings corresponding to the pair of sliding raceways of the third slide member. The pair of extension wings has a pair of contacting surfaces. A distance defined between the pair of contacting surfaces is slightly smaller than a distance defined between the pair of the sliding raceways of the third slide member so that the pair of sliding raceways urges the contacting surfaces to form a locating effect of frictional contact when the pair of sliding raceways of the third slide member are in touch with the contact surfaces.