A full-range speaker with phase plate includes a speaker body disposed with a bracket above and a phase plate including a phase plane. The bracket is adapted to the phase panel. The phase panel is fixed above the bracket. The opposite corners of the phase panel are provided with protruding support ribs, and each of the support ribs meets with each other. By adding the phase plate, the phase may be adjusted to prevent standing waves, and the frequency response characteristics of the speaker may be effectively improved, so that the overall frequency response curve of the full-range speaker is improved at 6 kHz-18 kHz, thereby smoothing the overall frequency response curve of the full-range speaker.