A connector mechanism includes a housing whereon an opening is formed, a socket, and a rotary casing for rotatably covering the opening. The rotary covering includes a main body, a pivoting portion, a stopping portion, and an engaging portion for engaging with an engaging structure of a plug as the plug is inserted into the opening and fastened on the socket so as to fix the plug. The connector mechanism further includes a resilient component for driving the rotary covering to rotate relative to the housing so that the engaging portion engages with the engaging structure of the plug as the plug is fastened on the socket, and a stopping component for stopping the stopping portion of the rotary covering as the resilient component drives the rotary covering to rotate relative to the housing.