A lateral stabilizing device for a working ladder, said working ladder comprising a folding body respectively on left and right sides of the working ladder, a set of supporting legs respectively on front and rear outer sides of the working ladder, an inwardly concave frame holding groove arranged on an outer side of at least one supporting leg, wherein the lateral stabilizing device includes: a rotary connecting seat for fixing the lateral stabilizing device to a bottom end of the at least one supporting leg, a rotary connecting slot corresponding to the frame holding groove, and a component hole disposed on an inner side of the rotary connecting slot; a rotary shaft inserted into the rotary connecting slot; a first main spring sleeved on the rotary shaft; a swing frame pivotally connected on the rotary shaft, characterized in that: the swing frame includes a ratchet wheel and teeth distributed around the ratchet; the first main spring is configured with a first positioning terminal disposed on the rotary connecting seat, and a first recovery terminal disposed on the ratchet wheel and forcing the swing frame to be turned upwardly into the frame holding groove; the lateral stabilizing device further includes: a swing component overlapped above the ratchet wheel, wherein one side of the swing component is provided with a pawl that engages with the teeth, and the other side of the swing component is provided with a disengaging pressing portion extending out of the component hole; a component shaft pivotally connected to the swing component and inserted into the rotary connecting slot; and a second main spring sleeved on the component shaft, wherein the second main spring is configured with a second positioning terminal disposed on the rotary connecting seat, and a second recovery terminal to position the swing component to control the pawl to rotate downward to engage with the teeth. a rotary connecting seat for fixing the lateral stabilizing device to a bottom end of the at least one supporting leg, a rotary connecting slot corresponding to the frame holding groove, and a component hole disposed on an inner side of the rotary connecting slot; a rotary shaft inserted into the rotary connecting slot; a first main spring sleeved on the rotary shaft; a swing frame pivotally connected on the rotary shaft, characterized in that: the swing frame includes a ratchet wheel and teeth distributed around the ratchet; the first main spring is configured with a first positioning terminal disposed on the rotary connecting seat, and a first recovery terminal disposed on the ratchet wheel and forcing the swing frame to be turned upwardly into the frame holding groove; the lateral stabilizing device further includes: a swing component overlapped above the ratchet wheel, wherein one side of the swing component is provided with a pawl that engages with the teeth, and the other side of the swing component is provided with a disengaging pressing portion extending out of the component hole; a component shaft pivotally connected to the swing component and inserted into the rotary connecting slot; and a second main spring sleeved on the component shaft, wherein the second main spring is configured with a second positioning terminal disposed on the rotary connecting seat, and a second recovery terminal to position the swing component to control the pawl to rotate downward to engage with the teeth. the swing frame includes a ratchet wheel and teeth distributed around the ratchet; the first main spring is configured with a first positioning terminal disposed on the rotary connecting seat, and a first recovery terminal disposed on the ratchet wheel and forcing the swing frame to be turned upwardly into the frame holding groove; the lateral stabilizing device further includes: a swing component overlapped above the ratchet wheel, wherein one side of the swing component is provided with a pawl that engages with the teeth, and the other side of the swing component is provided with a disengaging pressing portion extending out of the component hole; a component shaft pivotally connected to the swing component and inserted into the rotary connecting slot; and a second main spring sleeved on the component shaft, wherein the second main spring is configured with a second positioning terminal disposed on the rotary connecting seat, and a second recovery terminal to position the swing component to control the pawl to rotate downward to engage with the teeth. a swing component overlapped above the ratchet wheel, wherein one side of the swing component is provided with a pawl that engages with the teeth, and the other side of the swing component is provided with a disengaging pressing portion extending out of the component hole; a component shaft pivotally connected to the swing component and inserted into the rotary connecting slot; and a second main spring sleeved on the component shaft, wherein the second main spring is configured with a second positioning terminal disposed on the rotary connecting seat, and a second recovery terminal to position the swing component to control the pawl to rotate downward to engage with the teeth.