A lamp assembly comprises a fixed support and a rotary support clamped on the fixed support and capable of rotating relative to the fixed support. The rotary support comprises a limiting block and a damping module arranged on one side opposite to the other side where the limiting block is arranged, of the fixed support. The damping module comprises a fixing plate and a pressing plate for connecting the limiting block to the fixing plate. The fixing plate and the limiting block clamp the fixed support to generate damping. According to the lamp assembly, only a heat sink serving as a lamp cap and arranged on the rotary support is rotated and the entire lamp is not need to be adjusted through the fixed support, the rotary support and the damping module in the rotary support, and meanwhile, when the heat sink serving as the lamp cap is rotated to a certain angle, the irradiation angle of the lamp cap can be further fixed without external force and cannot rotate freely due to the damping module.