A ceiling mount lamp having a fixing structure capable of assisting heat dissipation is disclosed. The ceiling mount lamp includes a fixing unit including a frame body and a back plate, and a lighting unit installed between the frame body and the back plate. At least one side of the light guide plate is provided with a circuit board on which an LED unit is disposed, and at least one side between the frame body and the back plate of the fixing unit is mounted with a U-shaped fixing member. One outer surface of the U-shaped fixing member is fastened with the circuit board, and another outer surface of the U-shaped fixing member is provided with at least a hook part, which provides an elastic force to push against the circuit board and the LED unit, such that the LED unit is pressed close to the light guide plate.