The present invention provides a portable cutting tool, which comprises: a blade for cutting workpieces, the blade having a blade plane; a housing; and a moveable guard installed on the housing, wherein the guard is provided with a blade through-hole through which the blade passes, the guard moves between a first position and a second position with respect to the housing, when the guard is located at the first position, the blade does not pass through the blade through-hole, and when the guard is located at the second position, the blade passes through the blade through-hole; either the guard or the housing is provided with an arc guide rail, and the other has position-limiting members which are matched with the arc guide rail to limit the displacement of the guard along the normal direction of the arc guide rail.