Waterproof lamp

A waterproof lamp comprising a lamp holder, wherein a bulb (4) and a protective cover (5) are mounted on the lamp holder, and the protective cover (5) is located outside the bulb (4);

• a mounting seat (3) is arranged at a top of the lamp holder, and the bulb (4) is mounted at a top of the mounting seat (3);
• a mounting disc (2) is mounted on the lamp holder, the mounting seat (3) extends through the mounting disc (2), and a bottom end of the protective cover (5) is mounted in the mounting disc (2);
• the bottom end of the protective cover (5) is provided with a bottom ring (11), an outer ring surface of the bottom ring (11) is provided with a spiral tightening groove (12);
• the spiral tightening groove (12) does not communicate with an interior of the protective cover (5);
• a convex ball (9) provided on an inner ring surface of the mounting disc (2) is engaged into the spiral tightening groove (12), such that the bottom ring (11) is connected with the mounting disc (2);
• and
• a groove wall of the spiral tightening groove (12) has a spiral slope, the convex ball (9) and the spiral tightening groove (12) are engaged by the spiral slope, allowing the protective cover (5) to be rotated and locked into place during downward insertion into the mounting disc (2).