The invention provides a low-light attenuation electrodeless lamp bulb. The blub comprises an inner layer bulb shell, a middle layer bulb shell, a main amalgam, an auxiliary amalgam and an outer layer bulb shell, wherein the middle layer bulb shell encircles the inner layer bulb shell; the main amalgam and the auxiliary amalgam are arranged between the inner layer bulb shell and the middle layer bulb shell; the outer layer bulb shell encircles the middle layer bulb shell; the middle layer bulb shell can restrain Hg atomic spectral lines of which the wave lengths are less than 200 nanometers; working gas is filled between the inner layer bulb shell and the middle layer bulb shell and the amalgams are arranged between the inner layer bulb shell and the middle layer bulb shell; and a space between the middle layer bulb shell and the outer layer bulb shell is vacuum. The low-light attenuation electrodeless lamp bulb of the embodiment of the invention has the advantages of effectively reducing the light attenuation of fluorescent powder, improving the lighting effect of an electrodeless lamp, prolonging the service life of the electrodeless lamp, reducing the using amount of the filled gas and the amalgam and effectively lowering cost.