A cable management arm comprising: a first arm; a second arm; a frame pivotably connected between the first and second arms (10, 12); an extension board fixed to the bottom of the frame; a support seat having a support board; a first connection element connected to the first arm; a second connection element connected to the second arm; a third connection element connected to the support seat; the cable management arm installed to a first slide assembly and a second slide assembly; the first arm connected to the first slide assembly by the first connection element; the second arm connected to the first slide assembly by the second connection element; and the support seat connected to the second slide assembly by the third connection element; a first support member pivotably connected to the support seat and contacting the support board of the support seat; a second support member slidably connected to the first support member and retractable relative to the first support member; a first resilient member connected between the first and second support members (24, 26) so that the second support member is pulled relative to the first support member by the first resilient member; a slide pivotably connected to the bottom of the frame and contacting the extension board, the slide slidably connected to the second support member, and the first arm being located at a fixed first position by the first connection element, the second arm being located at a movable second position by the second connection element, the support seat being located at a fixed third position by the third connection element, when the second connection element of the second arm is moved away from the first connection element of the first arm, the frame is moved away from the support seat by sliding movement of the slide along the second support member, the slide moves the second support member to extend relative to the first support member, and the first support member swings relative to the support seat. a first arm; a second arm; a frame pivotably connected between the first and second arms (10, 12); an extension board fixed to the bottom of the frame; a support seat having a support board; a first connection element connected to the first arm; a second connection element connected to the second arm; a third connection element connected to the support seat; the cable management arm installed to a first slide assembly and a second slide assembly; the first arm connected to the first slide assembly by the first connection element; the second arm connected to the first slide assembly by the second connection element; and the support seat connected to the second slide assembly by the third connection element; a first support member pivotably connected to the support seat and contacting the support board of the support seat; a second support member slidably connected to the first support member and retractable relative to the first support member; a first resilient member connected between the first and second support members (24, 26) so that the second support member is pulled relative to the first support member by the first resilient member; a slide pivotably connected to the bottom of the frame and contacting the extension board, the slide slidably connected to the second support member, and the first arm being located at a fixed first position by the first connection element, the second arm being located at a movable second position by the second connection element, the support seat being located at a fixed third position by the third connection element, when the second connection element of the second arm is moved away from the first connection element of the first arm, the frame is moved away from the support seat by sliding movement of the slide along the second support member, the slide moves the second support member to extend relative to the first support member, and the first support member swings relative to the support seat.