A testing method is configured for testing parameters of a color wheel. The color wheel includes a color filter, which includes three sector-shaped filter segments and a motor for driving the filter segments of the color filter to rotate. The color filter is driven to rotate. Light is emitted toward the color filter of the color wheel, and reflected back by the color filter. Boundary impulses are generated according to changes in intensity of the light reflected back by the color filter. Based on relationships between the boundary impulses, central angles of the filter segments of the color wheel are calculated.