A cable management assembly, comprising: a first cable management arm; a second cable management arm movably connected to the first cable management arm; a supporting frame configured to support at least one of the first cable management arm and the second cable management arm; and a connecting device arranged on the supporting frame, the connecting device comprising: a base having a longitudinal body, the longitudinal body having a first end and a second end; an engaging member having an engaging part and an elastic part, wherein the engaging part is located adjacent to the first end of the base, and the engaging part is located at an engaging position in response to an elastic force of the elastic part; and an operating member having an operating part and a guiding part, wherein the operating part is located adjacent to the second end of the base; wherein one of the guiding part and the engaging member has a protruded structure formed with an arc surface or an inclined surface, and the other one of the guiding part and the engaging member has a recessed part extended with an abutting surface; wherein when the guiding part is moved in response to the operating member, the protruded structure is moved away from the recessed part to abut against the abutting surface in order to move the engaging part of the engaging member away from the engaging position; characterized in that the operating part of the operating member is extended beyond the second end of the base of the connecting device; wherein the operating member is configured to be operated through the operating part to longitudinally move from a first position to a second position, and the guiding part is configured to guide the engaging member in response to movement of the operating member, in order to move the engaging part of the engaging member away from the engaging position. a first cable management arm; a second cable management arm movably connected to the first cable management arm; a supporting frame configured to support at least one of the first cable management arm and the second cable management arm; and a connecting device arranged on the supporting frame, the connecting device comprising: a base having a longitudinal body, the longitudinal body having a first end and a second end; an engaging member having an engaging part and an elastic part, wherein the engaging part is located adjacent to the first end of the base, and the engaging part is located at an engaging position in response to an elastic force of the elastic part; and an operating member having an operating part and a guiding part, wherein the operating part is located adjacent to the second end of the base; wherein one of the guiding part and the engaging member has a protruded structure formed with an arc surface or an inclined surface, and the other one of the guiding part and the engaging member has a recessed part extended with an abutting surface; wherein when the guiding part is moved in response to the operating member, the protruded structure is moved away from the recessed part to abut against the abutting surface in order to move the engaging part of the engaging member away from the engaging position; a base having a longitudinal body, the longitudinal body having a first end and a second end; an engaging member having an engaging part and an elastic part, wherein the engaging part is located adjacent to the first end of the base, and the engaging part is located at an engaging position in response to an elastic force of the elastic part; and an operating member having an operating part and a guiding part, wherein the operating part is located adjacent to the second end of the base; wherein one of the guiding part and the engaging member has a protruded structure formed with an arc surface or an inclined surface, and the other one of the guiding part and the engaging member has a recessed part extended with an abutting surface; wherein when the guiding part is moved in response to the operating member, the protruded structure is moved away from the recessed part to abut against the abutting surface in order to move the engaging part of the engaging member away from the engaging position; the operating part of the operating member is extended beyond the second end of the base of the connecting device; wherein the operating member is configured to be operated through the operating part to longitudinally move from a first position to a second position, and the guiding part is configured to guide the engaging member in response to movement of the operating member, in order to move the engaging part of the engaging member away from the engaging position.