Illuminating lamp

1. A lamp comprising:

a base, an actuating power supply, a light source, a lamp tube and a lampshade;

wherein:

the base is provided with a first internal thread and a second internal thread;

the first internal thread of the base is located at an outside of the second internal thread;

the actuating power supply is mounted in the base;

the light source is mounted in the base;

the light source includes a support rack mounted in the base and a plurality of filaments mounted on the support rack and electrically connected with the actuating power supply;

the lamp tube is screwed onto the second internal thread of the base and covers the light source;

the lampshade is screwed onto the first internal thread of the base and covers the lamp tube;

the actuating power supply has a central portion provided with a through hole; and

the support rack of the light source has a bottom provided with a mounting post mounted in the through hole of the actuating power supply.

2. The lamp of claim 1 , wherein each of the plurality of filaments of the light source is secured on a top of the support rack and has a lower end electrically connected with the actuating power supply.

3. The lamp of claim 1 , wherein the support rack of the light source is provided with a limit plate located between the mounting post and the filaments.

4. The lamp of claim 1 , wherein the base includes a housing and a connector screwed into the housing.