A system for dynamically adjusting a color gamut of a display system, wherein the display system comprises a light source system and an imaging system, the light source system comprises an excitation light source and a narrow-spectrum primary-color light source, the imaging system comprises a spatial light modulation device and the system for dynamically adjusting the color gamut of the display system, wherein the system is suitable to be comprised in the imaging system, wherein the excitation light source emits excitation light which is processed to output primary-color light including at least one broad-spectrum primary-color light, the narrow-spectrum primary-color light source outputs at least one narrow-spectrum primary-color light, and the narrow-spectrum primary-color light and corresponding broad-spectrum primary-color light are combined and outputted to the imaging system, and wherein the system for dynamically adjusting the color gamut of the display system comprises: a light source luminance adjustment module comprising: a brightest pixel point acquisition module configured to calculate color coordinates and luminance of a pixel point with a maximum luminance in a frame of an image; a broad-spectrum primary-color light luminance generation module configured to calculate a required minimum luminance of the broad-spectrum primary-color light based on color coordinates and luminance of the primary-color light outputted by the light source system and the color coordinates and the luminance of the pixel point with the maximum luminance, and to calculate a luminance control value for controlling the excitation light source based on the minimum luminance; a narrow-spectrum primary-color light luminance generation module configured to calculate a required luminance of the narrow-spectrum primary-color light based on the required minimum luminance of the broad-spectrum primary-color light, and to calculate a luminance control value for controlling the narrow-spectrum primary-color light source based on the required luminance of the narrow-spectrum primary-color light; and a luminance signal output module configured to generate a light source luminance signal of the excitation light source based on the luminance control value for controlling the excitation light source, and generate a light source luminance signal of the narrow-spectrum primary-color light source based on the luminance control value for controlling the narrow-spectrum primary-color light source; and to output the light source luminance signals to the excitation light source and the narrow-spectrum primary-color light source respectively to adjust luminance of light emitted by the excitation light source and luminance of light emitted by the narrow-spectrum primary-color light source. a brightest pixel point acquisition module configured to calculate color coordinates and luminance of a pixel point with a maximum luminance in a frame of an image; a broad-spectrum primary-color light luminance generation module configured to calculate a required minimum luminance of the broad-spectrum primary-color light based on color coordinates and luminance of the primary-color light outputted by the light source system and the color coordinates and the luminance of the pixel point with the maximum luminance, and to calculate a luminance control value for controlling the excitation light source based on the minimum luminance; a narrow-spectrum primary-color light luminance generation module configured to calculate a required luminance of the narrow-spectrum primary-color light based on the required minimum luminance of the broad-spectrum primary-color light, and to calculate a luminance control value for controlling the narrow-spectrum primary-color light source based on the required luminance of the narrow-spectrum primary-color light; and a luminance signal output module configured to generate a light source luminance signal of the excitation light source based on the luminance control value for controlling the excitation light source, and generate a light source luminance signal of the narrow-spectrum primary-color light source based on the luminance control value for controlling the narrow-spectrum primary-color light source; and to output the light source luminance signals to the excitation light source and the narrow-spectrum primary-color light source respectively to adjust luminance of light emitted by the excitation light source and luminance of light emitted by the narrow-spectrum primary-color light source.